Showing papers in "Malaysian Journal of Microbiology in 2011"
72 citations
TL;DR: In this article, eleven fungal strains were tested for their ability to produce brown and reddish brown textile dyes using H-acid (1naphthol-8-amino-3, 6-disulfonic acid) as a dye precursor in the fermentation medium.
Abstract: Eleven fungal strains were tested for their ability to produce brown and reddish brown textile dyes using H-acid (1naphthol-8-amino-3, 6-disulfonic acid) as a dye precursor in the fermentation medium. All tested fungal strains exhibited high ability to produce dyes varying in both dye color (brown to reddish brown) and fastness properties to washing, perspiration and UV light. The produced dyes were subjected to further analysis for quantitative determination of dye components for investigation of their inter-relations as well as their role in dye color and stability.
34 citations
TL;DR: Fresh samples of lettuce, carrot and cucumber collected from different markets and vendors in Abuja Municipal Area Council, Federal Capital Territory, Nigeria were evaluated for bacterial loads using spread plate agar dilution method.
Abstract: Salad vegetables are essential part of people’s diet all around the world. They are usually consumed raw and often without heat treatment or thorough washing; hence have been known to serve as vehicles for the transmission of pathogenic microorganism associated with human diseases. Fresh samples of lettuce, carrot and cucumber collected from different markets and vendors in Abuja Municipal Area Council, Federal Capital Territory, Nigeria were evaluated for bacterial loads using spread plate agar dilution method. Bacterial loads ranged from 1.6 x 10 6 to 2.9 x 10 8 cfu/g. Escherichia coli, Klebsiella and Enterobacter were amongst the coliforms (lactose fermenters), while Proteus, Pseudomonas aeruginosa, Salmonella and Shigella were non-lactose fermenters associated with the samples. Staphylococcus aureus was isolated from majority of the samples.
33 citations
TL;DR: In this article, the location and distances of wells from septic tanks were determined using the Global Positioning System (GPS) device and a tape rule respectively, and all the wells sampled had high TABC (4.76±1.41 log CFU/mL) and TCC (2.29±0.67 log CFUs) counts which exceeded the international standard of 0 per 100 mL of potable water.
Abstract: In Nigeria, inadequate supply of pipe borne water is a major concern; hence many homes have wells as a source of water for household uses. The groundwater of forty wells in Agbowo community was assessed for Total Aerobic Bacteria Counts (TABC) and Total Coliform Counts (TCC). The location and distances of wells from septic tanks were determined using the Global Positioning System (GPS) device and a tape rule respectively. All the wells sampled had high TABC (4.76±1.41 log CFU/mL) and TCC (2.29±0.67 log CFU/mL) counts which exceeded the international standard of 0 per 100 mL of potable water. There were no significant differences in the bacterial counts between covered and uncovered wells (p>0.05). The mean distance (8.93±3.61m) of wells from the septic tanks was below the limit (15.24 m or 50 ft) set by United State Environmental Protection Agency (USEPA). TABC increased with a decrease in distance between the wells and septic tanks though not significant (p<0.05). A very weak positive correlation (r 2 =0.021) ensued between the distance from septic tank and CC, while a weak negative correlation (r 2 = ‒0.261) was obtained between the TCC and TABC. This study accentuates the need to set standards for the siting of wells from septic tanks while considering all possible sources of well contamination as well as treatment of ground water before use.
26 citations
TL;DR: Bacteriological examination of different brands of sachet water samples collected from different locations showed that only Vince water and Akudo table water was found to be safe for drinking while the other brands ofsachet water from mobile vendors in Owerri metropolis was not potable.
Abstract: Aims: Continuous increase in the sale and indiscriminate consumption of packaged drinking waters in Nigeria is of public health significance. In order to safe guard public health, it is essential that the available packaged water is of the highest quality. This study was carried out to evaluate the bacteriological quality of packaged water on sale in Owerri metropolis, Imo State of Nigeria. Methodology and Results: From 30 registered sachet water factories, 8 samples each was purchased randomly fifteen of the brands of sachet water all over Owerri metropolis in Imo State, Southeastern Nigeria. These were analyzed for presence of bacterial indicators of water quality. Four weeks later, a second batch of the samples was collected from other brands. A mean plate counts was taken and the organisms from each water sample identified using standard procedures. The results showed that 11 (73.3%) sachet water brands had growths of pathogenic organisms in the first batch while 10 (66.6%) had growth in the second batch. The isolates were identified to be Klebsilla spp., Serratia spp., Proteus spp., Pseudomonas aeruginosa and Chromobacterium spp. The study showed that Klebsiella pneumoniae [7(29.2%)] was the most predominant. This was closely followed by Serratia spp. [6(25.0%)] and Proteus mirabilis [6(25.0%)]. Pseudomonas aeruginosa [3(12.5%)] and Chromobacterium spp. [2(8.3%)] was least predominant. Mean total heterotrophic bacteria plate counts (HPC) per millilitre ranged from 0.0 to 6.0 x 10 2 CFU/mL at 22 ° C and 0.0 to 7.0 x 10 2 CFU/mL at 37 ° C (first batch) and 0.0 to 5.0 x 10 2 CFU/mL at 22 ° C and 0.0 to 10.0 x 10 2 CFU/mL at 37 ° C for the second batch. Thus they fell below the United States Environmental Protection Agency (USEPA) and World Health Organization (WHO) drinking water standard of 100 HPC per millilitre of water. Bacteriological examination of different brands of sachet water samples collected from different locations showed that only Vince water and Akudo table water was found to be safe for drinking while the other brands of sachet water from mobile vendors in Owerri metropolis was not potable. Conclusion, Significance and Impact of study: Hence, the bacteriological quality of some of the brands of sachet water on sale in Owerri was of poor quality index. The study suggests that sachet water could be a route of transmission of enteric pathogens among the populace. In order to safe guard public health, highest quality brands of sachet water is therefore advocated.
25 citations
TL;DR: The result indicates the potential usefulness of these plants especially Memecylon malabaricum and Cochlospermum religiosum, in treating microbial infections in humans and plants and justifies the need for further investigations and characterization of the bioactive compounds present in the methanolic extracts of the plants.
Abstract: The present study was carried out to evaluate the antimicrobial activity of the crude methanolic extracts of Memecylon malabaricum Clarke. (leaves), Cochlospermum religiosum Linn. (leaves and flowers) and Andrographis serpyllifolia Vahl. (leaves) using the standard disc diffusion assay against eight strains of bacterial species, viz., Staphylococcus aureus , Salmonella typhi, Enterobacter aerogenes, Pseudomonas aeruginosa, Xanthomonas oryzae pv. oryzae , Xanthomonas axonopodis pv. malvacearum, Bacillus cereus and Micrococcus sp. The extracts of the plants at a concentration of 1.25 mg/disc showed minimum to moderate activity against both Gram positive and Gram negative bacteria indicating a broad spectrum activity. A preliminary phytochemical screening was conducted on the selected plant extracts using standard qualitative procedures that revealed the presence of several secondary metabolites. The extracts failed to show antioxidant activity by reducing power assay. The result indicates the potential usefulness of these plants especially Memecylon malabaricum and Cochlospermum religiosum, in treating microbial infections in humans and plants and justifies the need for further investigations and characterization of the bioactive compounds present in the methanolic extracts of the plants.
25 citations
TL;DR: It is concluded that synergism associated with the combination of medicinal plants is doubtful, however, the synergistic or additive effect between garlic and conventional drugs to some strains of bacteria which are resistant to some conventional drugs, gives hope of fighting drug resistance.
Abstract: As part of the on-going search for potent and resistance-free antimicrobial medicinal plants, the antimicrobial and synergistic effects of the plants, Allium sativum (E1) and Gongronema latifolium (E2) on Escherichia coli and Staphylococcus aureus were investigated. The sensitivities of E. coli and S. aureus to E1 and E2 and the minimum inhibitory concentrations of the plant extracts, individually and in combination with themselves, and with ciprofloxacin (CPX) and ampicillin (AMP), were tested using standard procedures. E1 and E2 individually showed appreciable antimicrobial effect (zones of inhibition > 16mm). The combination of E1 and E2 against the test organisms was not effective due to antagonism between E1 and E2. E1 or E2 when combined with CPX, completely suppressed the effect of CPX against E. coli , and rather produced additive effect on S. aureus similar to the combination of E2 and AMP against S. aureus , although CPX alone was more effective than either E1 or E2, unlike AMP. Synergism was observed in the combination of E1 and AMP against S. aureus . It is concluded that synergism associated with the combination of medicinal plants is doubtful. However, the synergistic or additive effect between garlic and conventional drugs to some strains of bacteria which are resistant to some conventional drugs, gives hope of fighting drug resistance.
21 citations
TL;DR: A total of 245 yeast isolates from Gunung Halimun National Park were screened for cellulolytic activity using 0.2% cellulose-azure assay and the highest CMCase activity was identified as Trichosporon sporotrichoides van Oorschot and de Hoog UICC Y-286.
Abstract: A total of 245 yeast isolates from Gunung Halimun National Park (GHNP) were screened for cellulolytic activity using 0.2% cellulose-azure. The results showed that 16 isolates have cellulolytic activity using cellulose-azure assay. These isolates were further screened for carboxymethyl cellulase (CMCase), avicelase and cellobiase using specific substrates (carboxymethyl cellulosa, avicel and cellobiose) with Teather and Wood method. The results showed that 7 isolates have CMCase; 6 isolates have cellobiase; 2 isolates have CMCase and cellobiase; and 1 isolate has CMCase and avicelase and cellobiase activities. Isolate S 4121 has the highest CMCase activity and identified as Trichosporon sporotrichoides (van Oorschot) van Oorschot and de Hoog UICC Y-286.
15 citations
TL;DR: Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection and detection of biofilm forming organisms can help in appropriate antibiotic choice.
Abstract: Microorganisms adhere to non-living material or living tissue, and form biofilms made up of extracellular polymers/slime. Biofilm-associated microorganisms behave differently from free-floating bacteria with respect to growth rates and ability to resist antimicrobial treatments and therefore pose a public health problem. The objective of this study is to detect the prevalence of biofilm producers among Gram positive and Gram negative bacteria isolated from clinical specimens, and to study their antimicrobial susceptibility pattern. The study was carried out from October 2009 to March 2010, at the Department of Microbiology, Army Medical College/ National University of Sciences and Technology (NUST), Rawalpindi, Pakistan. Clinical specimens were received from various wards of a tertiary care hospital. These were dealt by standard microbiological procedures. Gram positive and Gram negative bacteria isolated were subjected to biofilm detection by congo red agar method (CRA). Antimicrobial susceptibility testing of those isolates, which showed positive results (slime production), was done according to the Kirby-Bauer disc diffusion technique. A total of 150 isolates were tested for the production of biofilm/slime. Among them, 81 isolates showed positive results. From these 81, 51 were Gram positive and 30 were Gram negative. All the 81(54%) slime producers showed reduced susceptibility to majority of antibiotics. Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection. Detection of biofilm forming organisms can help in appropriate antibiotic choice.
15 citations
14 citations
TL;DR: The use of SSF for the production of thermostable amylopullulanase by C. thermosulfurogenes SVM17 could, therefore, led to reduction in the overall cost of enzyme production.
Abstract: The endo acting enzyme with dual specificity towards α-1,4- and α-1,6-glycosidic linkages are named as amylopullulanase. The production of extracellular thermostable amylopullulanase by Clostridium thermosulfurogenes SVM17 was investigated in solid state fermentation (SSF). Coarse type wheat bran was found to be the best substrate among ten easily available complex organic substrates evaluated. The production of enzyme reached a peak in 72 h. A high level of enzyme was produced in wheat bran moistened with PYE medium with a moisture content of 73 %. The optimum temperature and pH for amylopullulanase production was 60 °C and 7.5, respectively. An inoculum size of 20 % resulted in maximum production of amylopullulanase. Under the optimum conditions the strain showed a maximum of 17,227 and 21,526 U of amylase and pullulanase activity, respectively per kilogram of bacterial bran (BB). The enzyme production was high in SSF than that in SmF. The use of SSF for the production of thermostable amylopullulanase by C. thermosulfurogenes SVM17 could, therefore led to reduction in the overall cost of enzyme production.
TL;DR: An endophytic fungus, Fusarium solani (Mart.) Sacc.
Abstract: An endophytic fungus, Fusarium sp. was isolated from yew bark of eastern Himalaya. Ethyl acetate extract from its fermentation broth displayed considerable antimicrobial activity against three Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis and Staphylococcus epidermidis), three Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli and Shigella flexneri) and two pathogenic fungi (Candida albicans and Candida tropicalis). The metabolite showed highest inhibition zone against K. pneumoniae (27 mm) and lowest against C. albicans (10 mm). Based on BLAST search analysis of ITS rDNA sequence, the fungus was identified as Fusarium solani (Mart.) Sacc. Phylogenetic trees were generated by four different methods. Phylogenetic tree generated by UPGMA method was used to establish possible phylogenetic relationships of the fungus with other F. solani isolates those exist as endophytes, pathogens and saprotrophs taken from database. The generated tree showed that all F. solani strains have a common endophytic ancestry which gave rise to six clades that radiate into four evolutionary lineages. The possible phylogenetic relationships of F. solani that exist in different lifestyle have been discussed in each clade.
TL;DR: There is potential in utilizing in situ enzymatic saccharification of biomass by using T. reesei and P. chrysosporium that may lead to an economical simultaneoussaccharification and fermentation process for the production of fuel ethanol.
Abstract: Three fungal species were evaluated for their abilities to saccharify pure cellulose. The three species chosen
represented three major wood-rot molds; brown rot (Gloeophyllum trabeum), white rot (Phanerochaete chrysosporium) and soft rot (Trichoderma reesei). After solid state fermentation of the fungi on the filter paper for four days, the saccharified cellulose was then fermented to ethanol by using Saccharomyces cerevisiae. The efficiency of the fungal species in saccharifying the filter paper was compared against a low dose (25 FPU/g cellulose) of a commercial cellulase. Total sugar, cellobiose and glucose were monitored during the fermentation period, along with ethanol, acetic acid and lactic acid. Results indicated that the most efficient fungal species in saccharifying the filter paper was T. reesei with 5.13 g/100 g filter paper of ethanol being produced at days 5, followed by P. chrysosporium at 1.79 g/100 g filter paper. No ethanol was detected for the filter paper treated with G. trabeum throughout the five day fermentation stage. Acetic acid was only produced in the sample treated with T. reesei and the commercial enzyme, with concentration 0.95 and 2.57 g/100 g filter paper, respectively at day 5. Lactic acid production was not detected for all the fungal treated filter paper after day 5. Our study indicated that there is potential in utilizing in situ enzymatic saccharification of biomass by using T. reesei and P. chrysosporium that may lead to an economical simultaneous saccharification and fermentation process for the production of fuel ethanol.
TL;DR: A highly thermostable amylopullulanase was purified to homogeneity from the culture filtrate of the Clostridium thermosulfurogenes SVM17 and the analysis of hydrolysis product of pullulan showed that maltotriose was the main product.
Abstract: A highly thermostable amylopullulanase was purified to homogeneity from the culture filtrate of the Clostridium thermosulfurogenes SVM17. On SDS-PAGE, the purified fraction having both amylase and pullulanase activities were observed as a single band. The molecular weight of the purified amylopullulanase on SDS-PAGE was 97 kDa. The optimum temperature for both amylase and pullulanase was 70 °C. The enzyme was completely stable at 70 °C for 2 h. The presence of 5% starch increased the thermal stability of the enzyme at 100 °C up to 2 h. Both amylase and pullulanase activities were optimum at pH 5.5 to 6.0 and were stable over a pH range of 4.0 to 6.5. The TLC analysis of the reaction products on starch showed that maltose was the main product along with trace amounts of glucose. The analysis of hydrolysis product of pullulan showed that maltotriose was the main product. At 5 mM concentration, Mn 2+ and Ag + strongly stimulated both amylase and pullulanase activities, where as Mg 2+ , Ca 2+ , Cu 2+ , Fe 3+ , Zn 2+ , Hg 2+ , EDTA, Cd 2+ and Li 2+ inhibited both amylase and pullulanase activities. When the concentration of metal ions was increased from 5 to10 mM, a further increase in amylase activity was observed in the presence of Ni 2+ , Mn 2+ and Co 2+ . Where as substantial decrease was observed at 10 mM concentration of Ag + , Pb 2+ and Ca 2+ .
TL;DR: P. vulgaris was identified as the major protease producer in optimized culture condition of 50 o C and pH6.5 and further research on optimization of other fermentation parameters using statistical tools with P. vulgarIS is needed to scale up the process.
Abstract: Aims: The present study was investigated to optimize and partially purify the proteases produced by the food borne bacterial strains. Methodology and Results: Four bacterial strains such as Bacillus cereus, Proteus vulgaris, P. mirabilis and Enterobacter aerogenes were isolated from food wastes. These strains were individually inoculated in to the formulated culture media supplied with three different concentrations (1:1 to 1:3) of raw milk as major substrate. Among the concentrations, 1:2 ratio of substrate supplied medium showed maximum (0.133 to 8.000 IU/mL) protease production by all the tested organisms. After optimization, the organisms were tested for protease production at various pH (3 to 9), and temperature (30 to 80 °C). The result showed that all the organisms were capable of producing maximum protease at pH 6 (8.533 to 10.133 IU/mL) and at 50 °C (8.666 to 10.666 IU/mL). The crude enzymes produced by the tested organisms were individually purified by two different methods viz sodium alginate and ammonium sulphate-butanol methods. The purity of the protease determined in these two methods was ranged between 3.24 to 5.44 I and 3.13 to 5.55 IU/mL respectively. The partially purified enzymes were further analysed through SDS-PAGE; accordingly the molecular weight of protein produced by the test organisms was determined in between 49.44 and 50.98 kDa. Conclusion, significance and impact of study: Among the tested strains P. vulgaris was identified as the major protease producer in optimized culture condition of 50 o C and pH6. The molecular mass of the partially purified protease of P. vulgaris was 50.32 KDa. Further research on optimization of other fermentation parameters using statistical tools with P. vulgaris is needed to scale up the process.
TL;DR: The result showed that dipotassium hydrogen phosphate and rice husk were significant factors for xylanase production (> 95% confidence levels) and full factorial Centre composite design (CCD) was used to optimize the two significant factors.
Abstract: The main aim of this study was to optimize production medium in solid state fermentation for production of xylanase using Brevibacillus borstelensis MTCC 9874. The organism was isolated from Morang district of Nepal and it was grown for 96 h in five different mineral salt solutions (MMS) with rice husk and MSS-1 was selected as a medium for further study based on xylanolytic activity measured using DNS method. Plackett Burman design (Minitab 15.1) was done with six variables viz. dipotassium hydrogen phosphate, rice husk, sodium chloride, magnesium sulphate, sodium carbonate and calcium chloride. The result showed that dipotassium hydrogen phosphate and rice husk were significant factors for xylanase production (> 95% confidence levels). Full factorial Centre composite design (CCD) was used to optimize the two significant factors. Response surface and contour plot were used to locate the optimal value of the two factors. There was 279.88% increase in xylanolytic activity after optimization of the medium. Study of effect of temperature on xylanolytic activity showed that maximum xylanolytic activity (6.58±1.1 IU/mL) was found at 60 °C. Optimum pH was found to be 7.6 (Xylanolytic activity = 6.81±2.32 IU/mL). Thermal stability study showed that the enzyme has a good stability at 60 °C (95.62%). Lineweaver – Burk plot showed that the enzyme has Vmax and Km values 0.1075 μg/mL .min and 1427.63 μg/mL respectively.
TL;DR: The present study showed that the diversity and occurrences of Fusarium species in forest soil was low compared to cultivated soils.
Abstract: A total of 46 isolates of Fusarium were isolated from six forest soil samples in Muka Head, Teluk Bahang, Pulau Pinang. Two Fusarium species were identified from the soil samples namely, F. solani (93.5%) and F. oxysporum (6.5%). The present study showed that the diversity and occurrences of Fusarium species in forest soil was low compared to cultivated soils.
TL;DR: The use of levofloxacin is suggested for MRSA treatment since overuse of vancomycin can lead to the development of van comycin resistance and more importantly it is beyond the scope of poor patients in developing countries like India.
Abstract: The study was carried out to determine the prevalence of MRSA, VRSA and their current antimicrobial susceptibility pattern to various non-β-lactam antimicrobial agents to record the current status of MRSA response to commonly used antistaphylococcal antibiotics in Aligarh, India for a period of two years. A total of 430 Staphylococcus aureus strains were isolated from various clinical samples. Two hundred ninety (67.44%) of S. aureus were isolated from pus and most of these were from orthopaedics 124 (28.85%) and surgery wards 99 (23.02%). One hundred thirty eight (32.09%) strains were confirmed to be methicillin resistant by both phenotypic and genotypic methods. More than 80% of MRSA strains were multidrug resistant. However, all were uniformly sensitive to vancomycin and linezolid. Levofloxacin was the drug found to be resistant in just 16.47% MRSA strains. Vancomycin is the drug of choice for MRSA treatment. However, regular screening should be done for vancomycin intermediate and vancomycin resistant strains of Staphylococcus aureus .We suggest the use of levofloxacin for MRSA treatment since overuse of vancomycin can lead to the development of vancomycin resistance and more importantly it is beyond the scope of poor patients in developing countries like India.
TL;DR: The presence and prevalence of two major H. pylori virulence associated genes among gastric biopsies of Pakistani children were investigated, detecting high frequency of cagA while vacA s1a and vacA m2 regions with vacAS1a/m2 genotype were predominant in H.pylori infected gastric Biopsy specimens.
Abstract: The vacuolating cytotoxin VacA and cytotoxin associated gene product CagA, encoded by vacA and cagA are major virulence determinants associated with pathogenesis of Helicobacter pylori. The presence and prevalence of two major H. pylori virulence associated genes among gastric biopsies of Pakistani children were investigated in the current study. Fifty one gastric biopsy specimens of children were analysed for 16S rRNA, vacA and cagA genes using PCR. The results showed that 21 (41.2%) biopsies were positive for H. pylori as determined by 16S rRNA PCR. In the 21 H. pylori positive gastric biopsies, 19 (90.5%) showed vacA s1a, 1 (4.75%) was vacA s1b and 1 (4.75%) was vacA s2 whereas, 5 (23.8%) were vacA m1 and 16 (76.2%) were vacA m2. None of the H. pylori positive biopsies carried vacA s1c subtype. The cagA gene was found in 13 (61.9%) of H. pylori infected biopsies and different vacA combinations were found with or without cagA gene. H. pylori was detected with high frequency of cagA while vacA s1a and vacA m2 regions with vacA s1a/m2 genotype were predominant in H. pylori infected gastric biopsies of children.
TL;DR: A careful manipulation of these nutrient substrates could help to optimise the production of this enzyme on a large scale.
Abstract: The effects of the various carbon and nitrogen substrates on the growth and polygalacturonase activity of Trichoderma viride (BITRS-1001) isolated from the tar sand deposit in Gbelejuloda-Irele Ondo State, Nigeria were investigated in submerged cultivation at 30 °C ± 2 °C. The commercial carbon and nitrogen substrates included sucrose, fructose, starch, maltose, lactose and peptone, sodium nitrate, urea and casein respectively. All the carbon substrates used supported the growth of T. viride (0.566 to 0.156 g/50 mL of culture medium) with starch supporting the highest biomass yield and sucrose the least biomass yield. Maximum polygalacturonase activity of 3033 U/mL was recorded in maltose medium. Maximum biomass yield on the nitrogen sources was observed in the organic nitrogen namely peptone and casein with values not significantly different from each other at p ≤ 0.05. In the determination of the crude enzyme activity on the nitrogen sources, maximum polygalacturonase activity of 12,400 U/mL was recorded in peptone medium. Hence, a careful manipulation of these nutrient substrates could help to optimise the production of this enzyme on a large scale.
TL;DR: The results proved that anaerobic and facultativelyAnaerobic bacteria consisting of Acinetobacter, Bacteroides thetaiotaomicron, Escherichia coli, and Caulobacter readily existed in the guts of termites and could be used as an industrial biocatalyst for biofuel production.
Abstract: Aims: Termites thrive in terrestrial ecosystems and play an important role in the bio-recycling of lignocellulose. The objective of this study is to isolate and detect bacteria from the termite gut of Coptotermes formosanus and to screen their various enzyme activities by qualitative methods. In addition, this study was aimed to isolate lignin and furfural tolerant strains for various industrial bioprocesses. Methodology and Results: In this study, 50 worker termites of Coptotermes formosanus were collected from dead trees, from a forest in Taichung, Taiwan in June 2008 and the composition of the microbial flora from the termite guts was analyzed by DGGE analysis. The results proved that anaerobic and facultatively anaerobic bacteria consisting of Acinetobacter, Bacteroides thetaiotaomicron, Escherichia coli, and Caulobacter readily existed in the guts of termites. Although the majority of these gut symbionts have not yet been cultivated or identified, some related bacteria were isolated. Two isolates 1-8 and 2-2 of Genus Bacillus, exhibited endocellulase, protease, lipase, amylase, peroxidase and lignin peroxidase activity. Under aerobic conditions, the growth density of isolate 1-8 cultured in 1000 ppm lignin containing MSM medium was two-folds higher than cultured in MSM medium without lignin. Furthermore, the isolate 1-8 was tolerant to 20 mM furfural supplemented in the MSM medium. HPLC analysis confirmed Bacillus isolate 1-8 could degrade up to 15 mM furfural. Conclusion, significance and impact of study: Hind gut bacteria from C. formosanus were detected by culture independent DGGE method. Also, Bacillus isolates 1-8 and 2-2 obtained by culture dependent methods could withstand higher concentration of furfural and as well as lignin. These isolates may be co-cultured with ethanologenic bacteria and be used as an industrial biocatalyst for biofuel production.
TL;DR: The optimal combination of the controllable factors (aeration; agitation and fermentation time) that will maximize the cell dry weight is studied, which results in an increase in lipase production.
Abstract: The effect of oxygen on lipase production by Penicillium chrysogenum was studied under two operating modes, controlled aeration rate tested and controlled agitation at dissolved oxygen concentration (DO) 1.00 vvm. Lipase production and cell dry weight were tested in a stirred batch fermenter 5 L. Improvement in oxygen transfer rate (OTR) either by aeration or agitation resulted in an increase in lipase production. Growth curves and lipase activities of P.chrysogenum were examined at agitation rates (200,400,600 rpm), aeration rates (2,4 vvm) at different fermentation periods (24,48,72,96,120 h). Response Surface Methodology (RSM) using Design Expert software was used to study the effect of aeration, agitation, and fermentation time on lipase activity and cell dry weight. These factors were analyzed using 2 1 . 3 2 level factorial design. An optimal set of conditions that maximize lipase production: (2 vvm aeration; 600 rpm agitation after 72 h) was obtained. The maximum lipase activity obtained was 240 U/mL. Beside lipase activity, this paper also studies the optimal combination of the controllable factors (aeration; agitation and fermentation time) that will maximize the cell dry weight.
TL;DR: Cocoa butter substitute synthesis was attempted in a reaction containing 1.2 IU/mg of lipase using palm oil and methyl stearate in hexane, and the reaction product being formed was analyzed qualitatively using Thin Layer Chromatography (TLC) and quantified by gas chromatography (GC) which showed 83.17 % conversion efficiency for CBS.
Abstract: A Bacillus sp. RK-3 isolated from soil initially produced 3.28 IU/mL of 1, 3 regiospecific lipase in medium containing 1.0% olive oil. After process optimization, 10.56 IU/mL of lipase was produced in medium containing sunflower oil 1.5 %, tryptone 2 %, Ca 2+ 20 mM using 3 % inoculum in 250 mL Erlenmeyer flask containing 50 mL of the medium at pH 7.0, 250 rpm and 30 °C for 36 h. Scale up in 10 L bioreactor with 7.5 L of the optimized medium yielded 16.41 IU/mL in 30 h resulting in net 6.0 fold increase in enzyme units as against initial units of 3.28 IU/mL obtained under unoptimized conditions. The productivity in 10 L bioreactor is 0.547 IU/mL/h as against initial of 0.091 IU/mL/h. The lipase exhibited 95.12 % stability in hexane, followed by THF (75.83 %) and petroleum ether (73.85 %) after 24 h of incubation. Cocoa butter substitute (CBS) synthesis was attempted in a reaction containing 1.2 IU/mg of lipase using palm oil and methyl stearate in hexane. The reaction product being formed was analyzed qualitatively using Thin Layer Chromatography (TLC) and quantified by gas chromatography (GC) which showed 83.17 % conversion efficiency for CBS in 24 h.
TL;DR: Two steps bioconversion of cortexolone (Reichstein’s compound S) to its � 1 -dehydro-11 β-hydroxy derivatives and prednisolone, was successfully performed by the use of C. elegans for the production of cortisol and predisonsolone from cortexolones.
Abstract: Two steps bioconversion of cortexolone (Reichstein’s compound S) to its � 1 -dehydro-11 β-hydroxy derivatives and prednisolone, was successfully performed by the use of C. elegans for the production of cortisol and prednisolone from cortexolone. The combinations of sequential reactions, 11 β-hydroxylation and � 1 -dehydrogenation were performed by immobilized spores of Cunninghamella elegans . The immobilization technique was carried by either entrapment in sodium alginate or by adsorption on silver, 8 micron glass wool method. Maximum production of cortisol and prednisolone were obtained after 72 h transformation period using immobilized spores of C. elegans of concentration 2 x 10 7 spores/mL for both entrapment and adsorption. The highest transformation efficiency was recorded on using 1.6% w/v glass wool (92%) compared to that when the fungal spores were entrapped in 3% alginate (84%). Each immobilized microbial system was stable and could be used for the sequential reactions repeatedly (operational period, 18 days using entrapped C. elegans in alginate beads and 45 days using adsorbed spores on glass wool).
TL;DR: The findings suggest that the antagonistic extracts from Rba.
TL;DR: Antibacterial tests demonstrated that SPCs showed inhibitory activity against the pathogenic bacteria Staphylococcus aureus, Bacillus subtilis and Salmonella typhi and antifungal activity against Candida albicans, Fusarium vasinfectum and Penicillium sp.
Abstract: Chitinases (designated as SPCs) were isolated from „Shilbilati‟ potatoes, a potato prototype cultivated in Bangladesh by affinity chromatography on a chitin column. SPCs agglutinated rat erythrocytes at the minimum concentration of 7 µg/mL and showed toxicity against brine shrimp nauplii with the LC50 value of 20 µg/mL. The chitinases also agglutinated seven bacterial strains among the twelve as studied. Pseudomonas aeruginosa, Bacillus subtilis and Salmonella typhi were the most sensitive towards the SPCs and were agglutinated at 1.2, 2.5 and 5.0 µg/mL protein concentrations respectively. Antibacterial tests demonstrated that SPCs showed inhibitory activity against the pathogenic bacteria Staphylococcus aureus, Bacillus subtilis and Salmonella typhi. Antifungal activity was investigated by the disc diffusion method. Five fungal species (Candida albicans, Aspergillus niger, Fusarium vasinfectum, Aspergillus fumigatus and Aspergillus flavus) and two fungal genus (Penicillium and Mucor sp.) were examined in the assay. SPCs showed antifungal activity against Candida albicans, Fusarium vasinfectum and Penicillium sp.
TL;DR: Response surface methodology (RSM) based on central composite rotatable design (CCRD) was used to determine the optimal levels of medium components, viz., soluble starch, tapioca flour, peptone, magnesium chloride and ferrous sulphate for enhanced thermostable amylopullulanase production by Clostridium thermosulfurogenes SVM17 in submerged fermentation.
Abstract: Response surface methodology (RSM) based on central composite rotatable design (CCRD) was used to determine the optimal levels of medium components, viz., soluble starch, tapioca flour, peptone, magnesium chloride and ferrous sulphate for enhanced thermostable amylopullulanase production by Clostridium thermosulfurogenes SVM17 in submerged fermentation. The design contains a total of 54 experimental trials with first 32 organized in a fractional factorial design and experimental trials from 33-40 and 51-54 involving the replication of the central points. Within the tested range of concentrations, all medium components were found significant. The optimum levels of nutrients for maximum production of enzyme were (% w/v): potato starch, 5.2; tapioca flour, 6.3; peptone, 2.5; MgCl2· 6H2O, 0.015 and FeSO4· 7H2O, 6.0 ppm. After optimization of medium components, the strain SVM17 showed 96 and 409 % increased amylase and pullulanase activities, respectively when compared with the non-optimized conditions.
TL;DR: Dgradation rates of both the compounds by the immobilized cells, in general, were far better than that by the free cells, and these strains can be effectively deployed for treatment of heterogeneous aromatic wastes.
Abstract: Simultaneous degradation of halogenated and non-halogenated aromatic compounds that are catabolised through different cleavage pathways is generally difficult due to biochemical incompatibility. However, free cells of a mixed culture of Pseudomonas sp. CP4 that degrades phenol through meta-pathway and Pseudomonas aeruginosa strain 3mT that degrades 3-chlorobenzoate through ortho-pathway was shown, earlier, to degrade mixtures of phenol/cresols and 3-chlorobenzoate in shake flasks. In the present study the degrading efficiency of these strains when immobilized (separately) in Ca-alginate gel beads was tested using a fluidized bed reactor. Complete mineralization of up to 5 mM equimolar mixture of phenol and 3-chlorobenzoate was observed when the beads were used at 1:1 ratio. From a 10 mM equimolar mixture although phenol was completely mineralized 3-chlorobenzoate degradation was not complete as evidenced by accumulation of some intermediary metabolites and the release of only 86% of inorganic chloride (Cl ¯ ). Degradation rates of both the compounds by the immobilized cells, in general, were far better than that by the free cells. With further studies to select suitable gel matrices and optimization of bioreactor conditions these strains can be effectively deployed for treatment of heterogeneous aromatic wastes.
TL;DR: The routine identification of mycobacterial strains isolated from patients in different locations in Egypt was confirmed by specific DNA fragment amplification, and multi drug resistant tuberculosis (MDR-TB) was approximately double time in 2008 compared with the value in 2007.
Abstract: The routine identification of mycobacterial strains isolated from patients in different locations in Egypt was confirmed by specific DNA fragment amplification. The susceptibilities of 72 Mycobacterium tuberculosis strains against the four antibiotics used in tuberculosis treatment (Isoniazid, INH; Rifampicin, Rif; Streptomycin, St and Ethambutol, E) were examined. Our results indicated that, multi drug resistant tuberculosis (MDR-TB) represents about 19.5% of the tested strains, whereas sensitive strains represented 26.4%. The genetic polymorphism of the tested strains was examined using RAPD analysis. Six selected strains represent the different antibiotic susceptibility groups were examined using RAPD fingerprinting. No difference between the strains was recorded using the RFLP analysis of amplified specific fragment. The discrimination power of RAPD analysis was inadequate to clarify the genetic correlation between the tested strains. MDR-TB was approximately double time in 2008 compared with the value in 2007. Most of the new MDRTB was correlated with resident dense population regions.