Showing papers by "National Dairy Research Institute published in 1981"
TL;DR: Protein production by Aspergillus terreus GN1 grown on 1.0% alkali‐treated bagasse was studied under various cultural conditions and highest crude protein percent corresponded with highest carboxymethyl cellulase and filter paper enzyme activities.
Abstract: Protein production by Aspergillus terreus GN1 grown on 1.0% alkali‐treated bagasse was studied under various cultural conditions. The maximum biomass protein content of 20.1% and protein recovery of 11.2% was obtained with an initial pH of 4.0, with 1/5 (v/v) inoculum in continuously shaken cultures grown for seven days. Protein content of the alkali‐treated bagasse was 3.0%. Highest crude protein percent also corresponded with highest carboxymethyl cellulase and filter paper enzyme activities.
52 citations
TL;DR: A β-galactosidase from Streptococcus thermophilus was purified to homogeneity by ammonium sulfate and acetone fractionation, gel filtration on Sephadex G-200, and ion exchange chromatography on DEAE-SephadeX A-50 and exhibited an optimum pH at 6.6–7.0 and an optimum temperature of 57°C.
Abstract: A β-galactosidase from Streptococcus thermophilus was purified to homogeneity by ammonium sulfate and acetone fractionation, gel filtration on Sephadex G-200, and ion exchange chromatography on DEAE-Sephadex A-50. The purified enzyme preparation exhibited an optimum pH at 6.6–7.0 and an optimum temperature of 57°C. The enzyme was stable at pH 6.8–7.0. Km and Vmax for the enzyme, using ortho-nitrophenyl β-D-galactopyranoside as the substrate, were 0.25 mM and 83 μmoles/mg protein/min, respectively. It was strongly inhibited by Hg++, Ag+, and Cu++ as well as pchloro-mercuri benzoate. The enzyme had a molecular weight of about 6 × 105 and was highly specific for β-galactoside bonds.
38 citations
TL;DR: Rhizopus nigricans showed maximum growth and lipase production at 30°C in 5 days at pH 6.0 and the medium supplemented with glucose stimulated maximum production of lipase, whereas that supplemented with galactose, mannitol, fructose, sucrose, lactose, and maltose stimulated less lipaseProduction.
19 citations
TL;DR: In this article, the optimum conditions for β-galactosidase production by K. fragilis were studied and it was shown that the mixture of whey with ammonium salts and partially digested proteins provided a nearly fourfold increase in enzyme production.
Abstract: Optimum conditions for β-galactosidase production byK. fragilis were studied. Enzyme production has a maximum after 8 –12 h of incubation. Composition of whey (from different sources) did not affect enzyme production. Different heat treatments also had no effect. Whey reconstituted to 8 –12 % total solids and adjusted to pH 4.0 afforded maximum enzyme production. Whereas inorganic nitrogen sources (specially ammonium salts) only slightly stimulated enzyme production, organic nitrogen sources (specially partially digested proteins) provided a nearly four-fold increase in enzyme production. Yeast extract and beef extract and industrial by-products like corn-steep liquor significantly stimulated enzyme production. Manganese and magnesium salts had a very little stimulation effect.
18 citations
TL;DR: Immunoreactive oestradiol-17β in milk was measured by radioimmunoassay in nine cross-bred dairy cows and the apparent oESTradiol7β concentration was found to be significantly higher in evening.
14 citations
TL;DR: With progressive lactation, the major changes from colostral fat were an increase in lower fatty acids and decline in oleic acid, which caused marked variations in saturated TG and diene TG and, to a smaller extent, in polyene TG.
Abstract: Milk fats obtained from colostrum and early, middle and late lactation samples of buffalo milk were analyzed for their triacylglycerol (TG) compositions. Each milk fat first separated by thin layer chromatography (TLC) into high, medium and low molecular weight TG. The TG fractions thus obtained were further segregated by argentation TLC, according to their degree of unsaturation into saturated,trans-monoene,cis-monoene, diene and polyene species. With progressive lactation, the major changes from colostral fat were an increase in lower fatty acids and decline in oleic acid. This caused, in turn, marked variations in saturated TG and diene TG and, to a smaller extent, in polyene TG. Monoene TG, bothcis andtrans, remained practically constant throughout. These trends were largely reversed toward the end of lactation.
13 citations
TL;DR: It is suggested that chromatin cyclic nucleotide phosphodiesterase may have a role post fertilization in cell growth and differentiation with no role in sperm motility which is regulated by similar enzymes present in sperm flagella.
7 citations
TL;DR: Growth and lipase production were suppressed by incorporation of lipids, namely olive oil, butter oil, tributyrin, tricaproin and tripropionin, into the growth medium.
7 citations
TL;DR: The enzyme was most active at 65°C and recorded an optimum pH at 7.0 and was strongly inhibited by Hg++, Ca++, Ni++, and Ag+ as well as parachloromercuribenoate.
Abstract: Beta-galactosidase (Beta-D-galactosidegalactohydrolase, EC 3.2.1.23) of Streptococcus cremoris H was partially purified by ammonium sulfate fractionation. Only 10% of the protein was recovered as enzyme protein and more than 50% of the enzyme in the crude extract was lost. A 2.6-fold purification only was achieved. The enzyme was most active at 65°C and recorded an optimum pH at 7.0. Km and Vmax with ortho-nitrophenyl beta-D galactopyranoside as the substrate were recorded as 0.384 mM and 12.6 μmoles/mg protein/min. Manganese ions activated the enzyme. The enzyme was strongly inhibited by Hg++, Ca++, Ni++, and Ag+ as well as parachloromercuribenoate.
6 citations
TL;DR: The augmentation in absorptive capacity of intestinal cells in protein-deficient rats was a temporary adaptation to the condition that resulted in reduced intestinal cell population, which resulted in an increase in intestinalcell population, return of absorptivecapacity of intestine cells to normal, and improvement in net absorption rates.
Abstract: The effects of protein deprivation and subsequent rehabilitation on the intestinal absorption of a mixture of amino acids were studied in albino rats. The absolute amounts of amino acids transported across the intestine were greater in rats fed for 28 days 17%casein diet than those fed 3% maize protein or no-protein diets. The absorption per unit intestinal DNA(termed as absorptive capacity) of amino acids, except L-arginine in males, was more in rats fed the 3% maize protein diet than those fed the casein diet. The changes in the absorptive capacity of two sexes, when fed the protein-free diet, were not similar. The males absorbed L-arginine and L-methionine, and females L-histidine and L-tryptophan at rates faster in the protein-free group than their counterparts in the casein group. The differences between protein-free and casein groups in the absorption of L-tryptophan and L-histidine in males and L-arginine and L-methionine in fe males were not significant. The augmentation in absorptive capacity of intestinal cells in protein-deficient rats was a temporary adaptation to the condition that re sulted in reduced intestinal cell population. Rehabilitation of protein-deficient rats for 32 days on the casein diet, resulted in an increase in intestinal cell popu lation, return ofabsorptive capacity of intestinal cells to normal, and improvement in net absorption rates. J. Nutr. Ill: 1513-1521, 1981.
5 citations
TL;DR: The study revealed that cortisol under normal conditions does not appear to be involved in the regulation of the cycle, and the level during the oestrous cycle was not significant.
Abstract: Changes in the concentration of cortisol were measured by radioimmunoassay in the blood plasma of buffaloes (Bubalus bubalis). There were minor fluctuations in the level during the oestrous cycle, but the differences between the days were not significant. The study revealed that cortisol under normal conditions does not appear to be involved in the regulation of the cycle.
TL;DR: In this paper, cow and buffalo milk fat were analyzed for carbonyls over 1 year to study the interrelationship among classes of carbonyl. The results showed that the proportion of methyl ketones was much higher in cow than in buffalo milk.
TL;DR: Of the five different nitrogen sources tested, peptone at the 2% level supported highest production of lipase, andCalcium, potassium and sodium citrate stimulated production of enzyme to the extent of 80, 60 and 47%, respectively.
TL;DR: Coliform counts increased rapidly in control samples at 37 C; however, consistently lower coliform counts were recorded in the butter samples containing potassium sorbate.
TL;DR: A study on the nutritional evaluation of processed cheddar cheese and spray-dried powder made from it, was undertaken in this paper, which showed that a Modified Protein Efficiency Ratio (PERD), Net Protein Utilization (NPU), and Digestibility Coefficient (DC) and also regeneration of certain organs, in protein depleted albino rats fed diets based on processed cheese and Spray-dired powder, were identical.
Abstract: A study on the nutritional evaluation of processed cheddar cheese and cheese spread powder made from it, was undertaken Levels of all constituents, except phosphorus and moisture contents, were significantly higher in cheese spray-dried powder as compared to processed cheese Biological evaluation of the products showed that a Modified Protein Efficiency Ratio (PERD), Net Protein Utilization (NPU), and Digestibility Coefficient (DC) and also regeneration of certain organs, in protein depleted albino rats fed diets based on processed cheese and spray-dired powder made from it, were identical
TL;DR: All of twenty thermonuclease deficient mutants lost the capacity to produce coagulase, enterotoxin, and lecithinase, however, these functions were regained upon reversion with visible light (Photoreactivation), thus suggesting a coordinated control mechanism for the synthesis and release of the above metabolites.
Abstract: A toxigenic strain of Staphylococcus aureus known to produce both thermonuclease and enterotoxin was exposed to ultraviolet radiations. Thermonuclease deficient mutants were recovered on methylgreen-DNA-agar medium. All of twenty thermonuclease deficient mutants lost the capacity to produce coagulase, enterotoxin, and lecithinase. However, these functions were regained upon reversion with visible light (Photoreactivation) thus suggesting a coordinated control mechanism for the synthesis and release of the above metabolites. These characteristics in most of the mutants remained stable for 3 months.
TL;DR: The milk yield of the first 120 days and subsequent cumulative part lactation yields up to 270 days were observed to be more efficient for indirect selection for the first lactation than direct selection on the basis of total first lactATION yield.
Abstract: The relative efficiency of selection based on part lactation compared to that of total first lactation was high. When the earlier parts of the lactation were considered, single third or fifth monthly milk yield gave a selection efficiency 1 to 6% higher than that obtained from total first lactation yield. The milk yield of the first 120 days and subsequent cumulative part lactation yields up to 270 days were observed to be more efficient for indirect selection for the first lactation than direct selection on the basis of total first lactation yield. For effecting early selection the first 120 days milk production could be used to advantage. Similarly, where there are difficulties in recording the yield daily throughout the lactation, the third or fifth monthly yield recording could be resorted to for selecting efficiently and to formulate culling plans for the herd.
TL;DR: Results are of interest on account of faster degradation of certain protein substrates of nondairy origin by lactobacilli which contribute significantly to texture and flavor development in cultured milk-based foods.
Abstract: Since little information is available on the role of Lactobacilli in the degradation of casein species (other than cow casein) and non-milk protein substrates, this study was undertaken to gather information on degradative ability of lactobacilli on different protein substrates. Progressive enhancement in the liberation of tyrosine with an increase in incubation period was recorded in all the cultures. As regards the degradative ability of lactobacilli on protein substrates of nondairy origin, an increasing trend in proteolysis rate was noted up to 10 days. Results are of interest on account of faster degradation of certain protein substrates of nondairy origin by lactobacilli which contribute significantly to texture and flavor development in cultured milk-based foods.
TL;DR: Aspergillus parasiticus NRRL 2999 and Aspergilli flavus K3 were examined for aflatoxin production in khoa and penetrated to a depth of 4 cm in the inoculated khoA samples stored at 28 and 37 C.