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1.
Krishna Gokul Divyashri Gangaraju Prapulla S. G. Muralidhara 《Neurochemical research》2015,40(9):1904-1918
Neurochemical Research - Prebiotic oligosaccharides are demonstrated to confer a wide spectrum of physiological benefits during pregnancy. In view of this, focused attempts are being directed... 相似文献
2.
Screening and selection of media components for lactic acid production using Plackett–Burman design 总被引:2,自引:0,他引:2
S. Krishnan S. G. Prapulla D. Rajalakshmi M. C. Misra N. G. Karanth 《Bioprocess and biosystems engineering》1998,19(1):61-65
Plackett–Burman design was used to efficiently select important media components influencing lactic acid production in a two step screening procedure. A total of 36 screening experiments were conducted for studying the effect of various media components such as carbon and nitrogen (simple and complex) sources, minerals/buffering agents and a specific inducer for the production of lactic acid by Lactobacillus plantarum NCIM 2084. The eleven ingredients chosen after the first screening experiments were further screened by a Plackett-Burman design consisting of 12 experiments. Liquefied starch, wheat bran extract, ammonium nitrate, manganese sulphate and sodium acetate were chosen as promising ingredients for further optimisation studies. The highest yield of 41.9?g/l of lactic acid was obtained at the end of 24 hours of fermentation which corresponded to 90% conversion, on the basis of sugar supplied. 相似文献
3.
Arenahalli Ningegowda Madhu Prashant Giribhattanavar Mandayam Singara Narayan Siddalingaiya Gurudutt Prapulla 《Biotechnology letters》2010,32(4):503-506
Vitamin B12 was produced by probiotic Lactobacillus plantarum in submerged fermentation (96 h) with successive anaerobic and aerobic phases of 48 h each to give 13 ng vitamin B12/g dry biomass. Sodium cyanide-mediated cell lysis, followed by benzyl alcohol/chloroform/water extraction, improved the release
of intracellular vitamin B12 for analysis. The presence of the K+ adduct of cyanocobalamin (m/z of 1394) was established using electron spray ionization–mass spectra; growth of a mutant of Escherichia coli in the presence of cyanocobalamin ascertained its bioavailability. 相似文献
4.
S Hari Krishna S G Prapulla N G Karanth 《Journal of industrial microbiology & biotechnology》2000,25(3):147-154
Isoamyl butyrate, an important fruity flavor ester, was synthesized using Rhizomucor miehei lipase immobilized on a weak anion exchange resin (Lipozyme IM-20) by the esterification of isoamyl alcohol and butyric acid.
The effects of various reaction parameters such as substrate and enzyme concentrations, substrate molar ratio, temperature
and incubation time have been investigated. Yields above 90% were obtained with substrate concentrations as high as 2.0 M.
No evidence of enzyme inhibition by butyric acid was present up to 1.0 M concentration. Acid inhibition and, to a small extent,
alcohol inhibition were evident above 1.0 M substrate concentration. Conversions reached a saturation value by the end of
24–48 h of incubation due to the accumulation of the water of reaction. The equilibrium was successfully pushed forward towards
esterification by removing the accumulated water using a molecular sieve.Journal of Industrial Microbiology & Biotechnology (2000) 25, 147–154.
Received 09 February 2000/ Accepted in revised form 24 June 2000 相似文献
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6.
Arenahalli Ningegowda Madhu Nanjaiah Amrutha Siddalingaiya Gurudutt Prapulla 《Probiotics and antimicrobial proteins》2012,4(2):90-97
The effect of a prebiotic (fructooligosaccharides) or a synbiotic components (prebiotic and probiotic) on the viability, proteolysis and antioxidant properties of probiotic and synbiotic yogurt during 28?days of storage at 4?°C has been investigated. Yogurt starters in conjunction with either probiotic bacteria Lactobacillus plantarum CFR 2194, Lactobacillus fermentum CFR 2192 and/or fructooligosaccharides (FOS) were used for yogurt preparation. Titratable acidity and pH of all yogurt samples followed a similar pattern of increase or decrease during storage. Proteolysis in synbiotic yogurts was found to be significantly (P?<?0.05) higher in comparison with that of control. The addition of prebiotics had no effect (P?=?0.17888) on the viability of yogurt starters during cold storage. No observable changes in the viability of probiotic cultures in probiotic groups. However, supplementation of FOS affected the growth significantly (P?<?0.05) in promoting the growth of L. plantarum and L. fermentum. Antioxidant activities, the index of nutritional value of yogurt, were monitored. Results showed that the DPPH-radical-scavenging activity (85?%) in synbiotic yogurt containing L. plantarum and FOS was significantly higher (P?<?0.05) in comparison with that of control yogurt (72?%). Total phenolics and the ferric reducing power were highest in synbiotic yogurts in comparison with that of other test samples during the entire period of storage. Addition of selected probiotics with FOS thus resulted in an improved functionality of yogurt. 相似文献
7.
Prapulla SG Jacob Z Chand N Rajalakshmi D Karanth NG 《Biotechnology and bioengineering》1992,40(8):965-970
In this study, an attempt has been made to maximize the lipid production using response surface methodology (RMS). Levels of nitrogen, carbon, and inoculum were chosen as factors. The results indicated that inoculum level was very important in lipid production, followed by carbon and nitrogen levels. At higher levels of inoculum, the strain was found to be more tolerant to higher concentrations of sugar, and significantly increased lipid production was noticed. Through the fitted models of second order, as per RSM, carbon at 10.24%, nitrogen at 0.37 g/L, and inoculum at the 20% level resulted in maximum biosynthesis of lipids. 相似文献
8.
DivyaShri Gangaraju Vytla Ramachandra Murty Siddalingaiya Gurudutt Prapulla 《Annals of microbiology》2014,64(1):229-237
Lactic cultures were screened for their ability to accumulate γ-aminobutyric acid (GABA) in the culture medium. Lactobacillus bulgaricus CFR 2028 produced the highest yields of GABA (22.7 mM) from the substrate monosodium glutamate (MSG). Instrumental characterization by high-performance liquid chromatography and structural characterization by mass spectrometry confirmed GABA production by L. bulgaricus CFR 2028. The differential production of GABA in complex and minimal media indicated that minimal medium (modified tryptone, yeast extract and glucose; TYG) supported the highest production of GABA (37 mM), thereby signifying that the acidic pH alone could have a significant bearing on the yield of GABA. This observation opens up avenues for the optimization of the medium components for yield maximization. The biotransformation kinetics of MSG was examined in batch experiments by varying initial MSG concentration (1–5 %). The Monod model was fitted to determine the kinetic parameters under the MSG uninhibited domain, and the MSG inhibited domain was represented well by Briggs–Haldane model. 相似文献
9.
Immobilized lipase from Rhizomucor miehei (Lipozyme IM-20) was used to catalyze the esterification reaction between isovaleric acid and ethanol to synthesize ethyl isovalerate in n-hexane. Response surface methodology based on a four-variable, five-level, central composite rotatable design was employed to optimize four important reaction variables—enzyme/substrate (E/S) ratio, substrate concentration, incubation time, and temperature—affecting the synthesis of ethyl isovalerate. The optimum conditions predicted for achieving maximum ester yield (500 mM) are as follows: E/S ratio, 48.41 g/mol; substrate concentration, 1 M; reaction time, 60 h; and temperature, 60°C. The predicted value matched well with the experimentally obtained value of 487 mM. 相似文献
10.
G.V. Chowdary S. Divakar S.G. Prapulla 《World journal of microbiology & biotechnology》2002,18(3):179-185
Immobilized lipase from Rhizomucor miehei (Lipozyme IM-20) was employed in the esterification of isovaleric acid and isoamyl alcohol to synthesize isoamyl isovalerate in n-heptane. Response surface methodology (RSM) based on a five-level, five-variable central composite rotatable design (CCRD) was used to evaluate the effects of important variables: enzyme concentration (20–40% w/w of acid), acid concentration (0.2–1.0 M), incubation period (24–120 h), alcohol concentration (0.25–1.25 M) and temperature (30–70 °C) on the esterification yield of isoamyl isovalerate. Extent of conversion was found to be excellent at all acid and alcohol concentrations employed in the range of 0.2–1.25 M, even at low enzyme concentration (20% w/w). The optimum conditions arrived at are as follows: 35% (w/w) enzyme concentration, 1.0 M acid concentration, 1.25 M alcohol concentration and 120 h incubation period, at 35 °C. Under these conditions, the predicted value was 680 mM ester matched very well with an experimental value of 678 mM. 相似文献