Showing papers on "Amylase published in 2007"
TL;DR: It is found that copy number of the salivary amylase gene (AMY1) is correlated positively with salivaries protein level and that individuals from populations with high-starch diets have, on average, more AMY1 copies than those with traditionally low-st starch diets.
Abstract: Starch consumption is a prominent characteristic of agricultural societies and hunter-gatherers in arid environments. In contrast, rainforest and circum-arctic hunter-gatherers and some pastoralists consume much less starch. This behavioral variation raises the possibility that different selective pressures have acted on amylase, the enzyme responsible for starch hydrolysis. We found that copy number of the salivary amylase gene (AMY1) is correlated positively with salivary amylase protein level and that individuals from populations with high-starch diets have, on average, more AMY1 copies than those with traditionally low-starch diets. Comparisons with other loci in a subset of these populations suggest that the extent of AMY1 copy number differentiation is highly unusual. This example of positive selection on a copy number-variable gene is, to our knowledge, one of the first discovered in the human genome. Higher AMY1 copy numbers and protein levels probably improve the digestion of starchy foods and may buffer against the fitness-reducing effects of intestinal disease.
1,247 citations
TL;DR: It proved that tea polyphenols were capable of binding and precipitating protein, suggesting a potential ability of TP to denature digestive enzymes, suggesting that TP might possess antinutritional properties.
319 citations
TL;DR: The B. subtilis JS-2004 strain produced high levels of thermostable α-amylase with characteristics suitable for application in starch processing and food industries, and was activated by Ca2+ (relative activity 117%).
310 citations
TL;DR: A highly thermostable alkaline amylase producing Bacillus sp.
185 citations
TL;DR: The interdependence between the activities of G WD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants.
Abstract: Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves of Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency are unknown. Using two different activity assays, we aimed to identify starch degrading enzymes from Arabidopsis, whose activity is affected by glucan phosphorylation. Breakdown of granular starch by a protein fraction purified from leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated by recombinant potato glucan, water dikinase (GWD). Using matrix-assisted laser-desorption ionization mass spectrometry several putative starch-related enzymes were identified in this fraction, among them β-AMYLASE1 (BAM1; At3g23920) and ISOAMYLASE3 (ISA3; At4g09020). Experiments using purified recombinant enzymes showed that BAM1 activity with granules similarly increased under conditions of simultaneous starch phosphorylation. Purified recombinant potato ISA3 (StISA3) did not attack the granular starch significantly with or without glucan phosphorylation. However, starch breakdown by a mixture of BAM1 and StISA3 was 2 times higher than that by BAM1 alone and was further enhanced in the presence of GWD and ATP. Similar to BAM1, maltose release from granular starch by purified recombinant BAM3 (At4g17090), another plastid-localized β-amylase isoform, increased 2- to 3-fold if the granules were simultaneously phosphorylated by GWD. BAM activity in turn strongly stimulated the GWD-catalyzed phosphorylation. The interdependence between the activities of GWD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants.
176 citations
TL;DR: Considering the cost effectiveness of the diet, and based on liver and plasma free amino acid levels and plasma protein fractions, 30% crude protein is recommended as the optimal dietary protein for L. rohita fingerlings.
Abstract: Labeo rohita, commonly called rohu is one of the most important fish species for aquaculture in India. Digestive enzyme response and metabolic profile of fingerling L. rohita to different dietary crude protein (CP) levels (viz. 25, 30, 35 and 40%) were studied in an attempt to optimize a practical diet formulation for this species. After 45 days of feeding, activity of digestive enzymes and metabolite concentrations were assayed. Amylase, lipase and alkaline phosphatase (ALP) activities were not influenced by the dietary protein, but proteolytic and acid phosphatase (ACP) activities varied (Pb0.05) between the treatments. Proteolytic activity showed a second order polynomial relationship with dietary crude protein (CP) as Y=0.0734X 2 +4.937X�68.37, r 2 =0.97. A positive correlation was observed between dietary CP and amylase (r 2 =0.78). All the metabolites except muscle glucose showed significant change corresponding to the dietary protein levels. Glucose and glycogen levels corresponded to the dietary carbohydrate levels. Muscle and plasma pyruvic acid increased as the crude protein in the diet increased, whereas liver pyruvic acid showed the opposite trend. Muscle protein content was not affected by dietary CP. Protein fractions in plasma (total protein, albumin and globulin) showed maximum values in 30% CP fed group. It is concluded that proteolytic activity and ACP are the major digestive enzymes responsive to dietary CP in L. rohita fingerlings. Considering the cost effectiveness of the diet, and based on liver and plasma free amino acid levels and plasma protein fractions, 30% crude protein is recommended as the optimal dietary protein for L. rohita fingerlings.
155 citations
TL;DR: The generation of Au nanoparticles (NPs) is reported, using a pure enzyme for the reduction of AuCl4-, with the retention of enzymatic activity in the complex.
Abstract: In this paper, we report the generation of Au nanoparticles (NPs), using a pure enzyme for the reduction of AuCl4-, with the retention of enzymatic activity in the complex. As a model system, α-amy...
138 citations
TL;DR: The most significant activity during the fermentation is the rapid and steady increase in the quantity of free amino acids throughout the fermentation, due to a consistently active proteinase activity by the fermentative microorganisms.
Abstract: The enzymic activities and biochemical changes in the principal food constituents of African locust bean were investigated. The reducing sugar level increased from 63 mg/g to 134 mg/g during the first 24 hr but subsequently decreased. Amylase activity was not detected. The lipase activities were detectable with the peak at 48 hr after the start of fermentation. The most significant activity during the fermentation is the rapid and steady increase in the quantity of free amino acids throughout the fermentation. This is due to a consistently active proteinase activity by the fermentative microorganisms. The number and quantities of each amino acids analysed also increased in the fermented beans. Glutamic acid, valine, aspartic acid and alanine were rapidly liberated during the fermentation. The changes observed are compared with the fermentation of other protein rich seeds.
129 citations
TL;DR: Although the proteolytic enzymes measured were at least in part comprised of serine-type proteases, other types such as metalo-proteases may play a significant role in the digestive process in red drum larvae and should be further characterized.
116 citations
TL;DR: In this article, α-Amylase was immobilized on zirconia via adsorption, and the support and the immobilized enzymes were characterized using XRD, IR spectra and N2 adaption studies.
116 citations
TL;DR: It can be concluded that retrograded amylose is not directly correlated with ERS and alternative mechanisms must be responsible for ERS formation.
Abstract: Starch structures from an extrusion process were stored at different temperatures to allow for molecular rearrangement (retrogradation); their thermal characteristics (DSC) and resistance to amylase digestion were measured and compared. The structure of four native and processed starches containing different amylose/amylopectin compositions (3.5, 30.8, 32, and 80% amylose content, respectively) before and after digestion was studied with small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD). Rearrangement of the amylose molecules was observed for each storage condition as measured by the DSC endotherm at around 145 degrees C. The crystalline organization of the starches after processing and storage was qualitatively different to that of the native starches. However, there was no direct correlation between the initial crystallinity and the amount of enzyme-resistant starch (ERS) measured after in vitro digestion, and only in the case of high-amylose starch did the postprocess conditioning used lead to a small increase in the amount of starch remaining after the enzymatic treatment. From the results obtained, it can be concluded that retrograded amylose is not directly correlated with ERS and alternative mechanisms must be responsible for ERS formation.
TL;DR: A method is described for the measurement of dietary fibre, including resistant starch (RS), non-digestible oligosaccharides (NDO) and available carbohydrates, except that for logistical reasons, d-sorbitol is used as the internal standard in place of glycerol.
Abstract: A method is described for the measurement of dietary fibre, including resistant starch (RS), non-digestible oligosaccharides (NDO) and available carbohydrates. Basically, the sample is incubated with pancreatic α-amylase and amyloglucosidase under conditions very similar to those described in AOAC Official Method 2002.02 (RS). Reaction is terminated and high molecular weight resistant polysaccharides are precipitated from solution with alcohol and recovered by filtration. Recovery of RS (for most RS sources) is in line with published data from ileostomy studies. The aqueous ethanol extract is concentrated, desalted and analysed for NDO by high-performance liquid chromatography by a method similar to that described by Okuma (AOAC Method 2001.03), except that for logistical reasons, d-sorbitol is used as the internal standard in place of glycerol. Available carbohydrates, defined as d-glucose, d-fructose, sucrose, the d-glucose component of lactose, maltodextrins and non-resistant starch, are measured as d-glucose plus d-fructose in the sample after hydrolysis of oligosaccharides with a mixture of sucrase/maltase plus β-galactosidase.
TL;DR: Replacing soybean meal with FSBM in diet increased the activities of trypsin, lipase, and protease significantly in intestinal content of starter broilers and enhanced the protease activity of grower broilers.
TL;DR: The results shown in the current study demonstrate that C. glutamicum displaying α-amylase has a potential to directly convert soluble starch to amino acids.
Abstract: We engineered a Corynebacterium glutamicum strain displaying α-amylase from Streptococcus bovis 148 (AmyA) on its cell surface to produce amino acids directly from starch. We used PgsA from Bacillus subtilis as an anchor protein, and the N-terminus of α-amylase was fused to the PgsA. The genes of the fusion protein were integrated into the homoserine dehydrogenase gene locus on the chromosome by homologous recombination. l-Lysine fermentation was carried out using C. glutamicum displaying AmyA in the growth medium containing 50 g/l soluble starch as the sole carbon source. We performed l-lysine fermentation at various temperatures (30–40°C) and pHs (6.0–7.0), as the optimal temperatures and pHs of AmyA and C. glutamicum differ significantly. The highest l-lysine yield was recorded at 30°C and pH 7.0. The amount of soluble starch was reduced to 18.29 g/l, and 6.04 g/l l-lysine was produced in 24 h. The l-lysine yield obtained using soluble starch as the sole carbon source was higher than that using glucose as the sole carbon source after 24 h when the same amount of substrates was added. The results shown in the current study demonstrate that C. glutamicum displaying α-amylase has a potential to directly convert soluble starch to amino acids.
TL;DR: This is the first report identifying α‐glucosidase inhibitory activity in B. racemosa seed extracts and assigning to bartogenic acid an α‐amylase and amyl enzyme inhibitory property.
Abstract: Barringtonia racemosa presents a wide range of therapeutic applications. In the course of identifying bioactives from Indian medicinal plants it was observed that the hexane, ethanol and methanol extracts of B. racemosa seeds displayed potent yeast and intestinal alpha-glucosidase inhibitory activities. The methanol extract was found to be superior among them. However, none of the extracts exhibited pancreatic alpha-amylase inhibitory activity, rather the ethanol and methanol extracts accelerated the alpha-amylase enzyme activity. Interestingly, however, bartogenic acid isolated from the methanol extract inhibited alpha-amylase also. This is the first report identifying alpha-glucosidase inhibitory activity in B. racemosa seed extracts and assigning to bartogenic acid an alpha-glucosidase and amylase inhibitory property. The presence of bartogenic acid in B. racemosa seeds as a major compound is also reported for the first time in this communication.
TL;DR: An overview of current models of starch breakdown in leaves is provided and it is now apparent that glucan phosphorylation is required for normal rates of starch mobilisation to occur, although a detailed understanding of this step is still lacking.
Abstract: The aim of this article is to provide an overview of current models of starch breakdown in leaves. We summarise the results of our recent work focusing on Arabidopsis, relating them to other work in the field. Early biochemical studies of starch containing tissues identified numerous enzymes capable of participating in starch degradation. In the non-living endosperms of germinated cereal seeds, starch breakdown proceeds by the combined actions of α-amylase, limit dextrinase (debranching enzyme), β-amylase and α-glucosidase. The activities of these enzymes and the regulation of some of the respective genes on germination have been extensively studied. In living plant cells, additional enzymes are present, such as α-glucan phosphorylase and disproportionating enzyme, and the major pathway of starch breakdown appears to differ from that in the cereal endosperm in some important aspects. For example, reverse-genetic studies of Arabidopsis show that α-amylase and limit-dextrinase play minor roles and are dispensable for starch breakdown in leaves. Current data also casts doubt on the involvement of α-glucosidase. In contrast, several lines of evidence point towards a major role for β-amylase in leaves, which functions together with disproportionating enzyme and isoamylase (debranching enzyme) to produce maltose and glucose. Furthermore, the characterisation of Arabidopsis mutants with elevated leaf starch has contributed to the discovery of previously unknown proteins and metabolic steps in the pathway. In particular, it is now apparent that glucan phosphorylation is required for normal rates of starch mobilisation to occur, although a detailed understanding of this step is still lacking. We use this review to give a background to some of the classical genetic mutants that have contributed to our current knowledge.
TL;DR: The effect of chitosan coating in fresh-cut mushroom preservation, including microbiological, enzyme activities, colour characteristics and chemical quality attributes, was examined in this paper, where the authors showed that increasing the concentration of chito-sans coating resulted in higher contents of total soluble solids (TSS), total acidity and TSS/T acid ratio of fresh cut mushroom.
Abstract: The effect of chitosan coating in fresh-cut mushroom preservation, including microbiological, enzyme activities, colour characteristics and chemical quality attributes, was examined. However, application of chitosan coating to enzyme activity control and quality maintenance of fresh-cut mushroom was investigated. Fresh-cut mushroom were treated with aqueous solution containing 5, 10 and 20 g of chitosan/1 L, placed in polyethylene bags, and then stored at 4°C. Changes in total phenolic content, and cellulase (CEL), total amylase, α and β amylase, laccase (LAC), phenylalanine ammonia lyase (PAL), peroxidase (POD), catalase (CAT) and polyphenoloxidase (PPO) enzymes activities were measured. Applications of chitosan coating delayed discoloration associated with reduced enzyme activities of LAC, PAL, POD, CAT and PPO as well as lowered total phenolic content. Also, it slowed down texture changes associated with reduced enzyme activities of CEL, total amylase and α-amylase. Results showed that increasing the concentration of chitosan coating resulted in higher contents of total soluble solids (TSS), total acidity and TSS/T acid ratio of fresh-cut mushroom. In mushroom, during storage at 4°C for 15 days, 20 g/kg chitosan coating inhibited the growth of total bacteria, yeasts and moulds counts. Chitosan also had a good effect on the evolution of the colour characteristics and parameters (C* and BI) of fresh-cut mushroom during storage at 4°C. The results showed that increasing the concentration of chitosan coating enhanced the beneficial effects of chitosan on extended shelf-life and maintained quality of fresh-cut mushroom.
TL;DR: In vitro results indicated that MGAM activity is inhibited by α-amylase digested starch product “brake” and contributes only 20% of mucosal α-glucogenic activity, which may contribute to highly efficient glucogenesis from low-starch diets and play a role in meeting the high requirement for glucose during children's brain maturation.
Abstract: BACKGROUND: Starches are the major source of dietary glucose in weaned children and adults. However, small intestine alpha-glucogenesis by starch digestion is poorly understood due to substrate structural and chemical complexity, as well as the multiplicity of participating enzymes. Our objective was dissection of luminal and mucosal alpha-glucosidase activities participating in digestion of the soluble starch product maltodextrin (MDx). PATIENTS AND METHODS: Immunoprecipitated assays were performed on biopsy specimens and isolated enterocytes with MDx substrate. RESULTS: Mucosal sucrase-isomaltase (SI) and maltase-glucoamylase (MGAM) contributed 85% of total in vitro alpha-glucogenesis. Recombinant human pancreatic alpha-amylase alone contributed <15% of in vitro alpha-glucogenesis; however, alpha-amylase strongly amplified the mucosal alpha-glucogenic activities by preprocessing of starch to short glucose oligomer substrates. At low glucose oligomer concentrations, MGAM was 10 times more active than SI, but at higher concentrations it experienced substrate inhibition whereas SI was not affected. The in vitro results indicated that MGAM activity is inhibited by alpha-amylase digested starch product "brake" and contributes only 20% of mucosal alpha-glucogenic activity. SI contributes most of the alpha-glucogenic activity at higher oligomer substrate concentrations. CONCLUSIONS: MGAM primes and SI activity sustains and constrains prandial alpha-glucogenesis from starch oligomers at approximately 5% of the uninhibited rate. This coupled mucosal mechanism may contribute to highly efficient glucogenesis from low-starch diets and play a role in meeting the high requirement for glucose during children's brain maturation. The brake could play a constraining role on rates of glucose production from higher-starch diets consumed by an older population at risk for degenerative metabolic disorders.
TL;DR: Aspergillus species isolated from various seeds were screened for their ability to produce amylase and a selected strain, JGI 12, showed the highest amyl enzyme activity in solid state fermentation.
Abstract: Aspergillus species isolated from various seeds were screened for their ability to produce amylase. A selected strain, Aspergillus sp. JGI 12, showed the highest amylase activity in solid state fermentation. Different substrates were screened for enzyme production. Coconut oil cake, groundnut oil cake and rice bran were found to be very good substrates for enzyme production. Different combinations; wheat bran : groundnut oil cake : rice bran (1:2:2) was used which resulted in higher enzyme titre. This combination of substrates was used for further studies on amylase production and characterization. The enzyme amylase was found to be thermostable and active at wide range of pH.
Key words: fungal amylase, Aspergillus sp. JGI 12, solid state fermentation, solid substrate, enzyme production.
TL;DR: The extracellular glucoamylase in thesupernatant of the cell culture of the marine yeast Aureobasidium pullulans N13d was purified to homogeneity with a 7.3-fold increase in specific activity as compared to the concentrated supernatant by ammonium sulfate fractionation and gel filtration chromatography.
TL;DR: In this article, the co-production of extracellular thermostable alpha-amylase and beta-galactosidase by Bacillus subtilis, a bacterium isolated from fresh sheep's milk, was investigated.
TL;DR: Results indicate that efficient simultaneous saccharification and fermentation of raw corn starch to L-lysine were achieved by C. glutamicum secreting AmyA using the cspB promoter and signal sequence.
Abstract: Corynebacterium glutamicum is an important microorganism in the industrial production of amino acids. We engineered a strain of C. glutamicum that secretes α-amylase from Streptococcus bovis 148 (AmyA) for the efficient utilization of raw starch. Among the promoters and signal sequences tested, those of cspB from C. glutamicum possessed the highest expression level. The fusion gene was introduced into the homoserine dehydrogenase gene locus on the chromosome by homologous recombination. L-Lysine fermentation was conducted using C. glutamicum secreting AmyA in the growth medium containing 50 g/l of raw corn starch as the sole carbon source at various temperatures in the range 30 to 40°C. Efficient L-lysine production and raw starch degradation were achieved at 34 and 37°C, respectively. The α-amylase activity using raw corn starch was more than 2.5 times higher than that using glucose as the sole carbon source during L-lysine fermentation. AmyA expression under the control of cspB promoter was assumed to be induced when raw starch was used as the sole carbon source. These results indicate that efficient simultaneous saccharification and fermentation of raw corn starch to L-lysine were achieved by C. glutamicum secreting AmyA using the cspB promoter and signal sequence.
TL;DR: In this paper, the health-relevant functional benefits of Lactobacillus bulgaricus (LBS) fermented milk and soymilk were investigated and targeted for management of hyperglycemia and related complication of hypertension using in vitro models.
Abstract: The health-relevant functional benefits of Lactobacillus bulgaricus and Lactobacillus acidophilus fermented milk and soymilk were investigated and targeted for management of hyperglycemia and related complication of hypertension using in vitro models. Free radical scavenging-linked antioxidant activity and enzyme inhibitory activities linked to hyperglycemia (α – amylase and α−glucosidase) and hypertension (angiotensin – I converting enzyme, ACE) of fermented substrates were evaluated using in vitro assays. These activities were correlated to phenolic and lactic acid contents. In spite of total phenolic content decreasing over 24 h, the free radical scavenging-linked antioxidant activity increased. α−Glucosidase inhibitory activity increased with fermentation, with higher activity in soymilk substrate. α–Amylase inhibitory activity was high in milk substrate throughout the fermentation and in soymilk it increased from a lower initial activity. Initial ACE inhibitory activity was high in soymilk and was ma...
TL;DR: In this paper, α-amylase from mung beans (Vigna radiata) was immobilized on two different matrices, Amberlite MB 150 and chitosan beads.
Abstract: α-Amylase from mung beans (Vigna radiata) was immobilized on two different matrices, Amberlite MB 150 and chitosan beads. Maximum immobilization obtained was 72% and 69% in case of Amberlite and chitosan beads, respectively. The pH optima of soluble α-amylase were 5.6, whereas that for immobilized amylase on chitosan and Amberlite was 7.0. Soluble amylase and Amberlite immobilized amylase showed maximum activity at 65 °C, whereas chitosan immobilized amylase showed maximum activity at 75 °C. α-Amylase immobilized on Amberlite showed apparent Km of 2.77 mg/ml, whereas α-amylase immobilized on chitosan showed an apparent Km of 5 mg/ml. The Amberlite-amylase and chitosan-amylase showed a residual activity of 43% and 27%, respectively, after 10 uses. The loss of activity for free amylase after 100 days of storage at 4 °C was 70%, whereas that for Amberlite- and chitosan-amylases, under the same experimental conditions, the losses were 45% and 55%, respectively. The easy availability of mung bean α-amylase, the ease of its immobilization on low-cost matrices and good stability upon immobilization in the present study makes it a suitable product for further use in industrial applications.
TL;DR: Evaluation of the influence of fermentation components on extracellular acid amylase production by an isolated fungal strain Aspergillus awamori shows positive results.
Abstract: Aims: Evaluation of the influence of fermentation components on extracellular acid amylase production by an isolated fungal strain Aspergillus awamori.
Methods and Results: Eight fungal metabolic influential factors, viz. soluble starch, corn steep liquor (CSL), casein, potassium dihydrogen phosphate (KH2PO4) and magnesium sulfate (MgSO4·7H2O), pH, temperature and inoculum level were selected to optimize amylase production by A. awamori using fractional factorial design of Taguchi methodology. Significant improvement in acid amylase enzyme production (48%) was achieved. The optimized medium composition consisted of soluble starch – 3%; CSL – 0·5%; KH2PO4– 0·125%; MgSO4·7H2O – 0·125%; casein – 1·5% at pH 4·0 and temperature at 31°C.
Conclusion: Optimization of the components of the fermentation medium was carried out using fractional factorial design of Taguchi's L-18 orthogonal array. Based on the influence of interaction components of fermentation, these could be classified as the least significant and the most significant at individual and interaction levels. Least significant factors of individual level have higher interaction severity index and vice versa at enzyme production in this fungal strain. The pH of the medium and substrate (soluble starch) showed maximum production impact (60%) at optimized environment. Temperature and CSL were the least influential factors for acid amylase production.
Significance and Impact of the Study: Acid amylase production by isolated A. awamori is influenced by the interaction of fermentation factors with fungal metabolism at individual and interaction levels. The pH of the fermentation medium and substrate concentration regulates maximum enzyme production process in this fungal strain.
TL;DR: No proteolytic and amylolytic activities were detected using conventional substrates in the digestive system of the adult suggesting no significant protein and carbohydrate digestion occurs in the adult beetle which does not need to feed.
TL;DR: Production of α-amylase by Bacillus amyloliquefaciens, under solid substrate fermentation (SSF) was investigated in shaken-culture and the temperature of fermentation was found to be most crucial factor in α-Amylase production.
TL;DR: Results suggest that CCK and PY work antagonistically in the exocrine pancreas of yellowtail, suggesting the stored enzyme was secreted from Pancreas post-prandially.
Abstract: In fish, the regulation of digestive enzyme secretion by hormonal control such as cholecystokinin (CCK) and neuropeptide Y (NPY)-related peptide is not well understood. To investigate the roles of fish CCK and peptide Y (PY) in digestive enzyme secretion, mRNA levels of CCK and PY, pyloric caeca enzyme activities and mRNA levels of pancreatic digestive enzymes (lipase, trypsin and amylase) were measured at pre- and post-prandial stages in yellowtail. Pyloric caeca were sampled at 0, 0.5, 1.5, 3, 6, 12, 24 and 48 h after feeding. The mRNA levels of trypsin and amylase increased after feeding, suggesting that transcription was induced by feed ingestion. Digestive enzyme activities decreased in exocrine pancreas after feeding, suggesting the stored enzyme was secreted from pancreas post-prandially. mRNA levels for CCK displayed a time-dependent increase, peaking between 1.5 and 3 h after-feeding followed by a rapid decrease 3 to 6 h after feeding. The mRNA expression pattern of PY was inverse to the pattern of CCK, decreasing until 1.5 h after feeding and then rising to initial levels by 12 h after feeding. These results suggest that CCK and PY work antagonistically in the exocrine pancreas of yellowtail.
01 Jan 2007
TL;DR: The enzyme amylase was found to be thermostable and active at wide range of pH, which resulted in higher enzyme titre.
Abstract: Aspergillus species isolated from various seeds were screened for their ability to produce amylase. A selected strain, Aspergillus sp. JGI 12, showed the highest amylase activity in solid state fermentation. Different substrates were screened for enzyme production. Coconut oil cake, groundnut oil cake and rice bran were found to be very good substrates for enzyme production. Different combinations; wheat bran : groundnut oil cake : rice bran (1:2:2) was used which resulted in higher enzyme titre. This combination of substrates was used for further studies on amylase production and characterization. The enzyme amylase was found to be thermostable and active at wide range of pH.
TL;DR: Pretreated corn soluble starch with alpha-amylase was sufficient to drive the fermentation and to convert 96% substrate to ethanol, and fed-batch fermentation by free C. tropicalis cells increased the final concentration to 56 g ethanol/l, reaching published values for Saccharomyces cerevisiae recombinant strains expressing both alpha- amylase and glucoamylases.