Babu Vakil - Academia.edu (original) (raw)

Papers by Babu Vakil

PubMed, Oct 1, 1989

A sensitive assay for staphylococcal nuclease involving incubation of the enzyme sample with heat... more A sensitive assay for staphylococcal nuclease involving incubation of the enzyme sample with heat-denatured [3H]thymidine labelled DNA from E. coli, precipitation with trichloroacetic acid and measurement of the radioactivity of acid-soluble nucleotides released has been developed. The assay is sensitive enough to be used for comparing the levels of nucleases elaborated by different strains of S. aureus as well as for determining the extent of contamination of S. aureus in food and water samples even at levels at which the conventional spectrophotometric and toluidine blue-DNA methods are totally inadequate.

Archives of Microbiology, Oct 1, 1984

Besides the well-known heat-stable extracellular staphylococcal nuclease (EC 3.1.4.7) and cell su... more Besides the well-known heat-stable extracellular staphylococcal nuclease (EC 3.1.4.7) and cell surface bound nuclease, one more nuclease, which is heat-labile, has been identified and purified on phosphorylated cellulose column and characterized. Analyses by Sephadex G-75 gel chromatography indicates that the heat-labile cellular nuclease has molecular weight of about 16,000 similar to those of extracellular and cell-surface bound nucleases. Like the heat-stable nucleases, the heat-labile enzyme acts on both DNA and RNA, is more active on heat-denatured DNA, requires Ca2+ ions for activity and maximum catalytic activity is observed at pH 9.8-10 and at 45 degrees C. The results suggest that the three enzymes have properties strikingly similar to one another and therefore may be related structurally.

Probiotics are live microorganisms which, when administered in adequate amounts confer health ben... more Probiotics are live microorganisms which, when administered in adequate amounts confer health benefit(s) on the host. They are produced by fermentation technology and find applications in production of functional foods and pharmaceutical formulations. They play several roles in promoting & maintaining human health. One of the most notorious contaminants in dairy and probiotic fermentation industries are bacteriophages. A leading Indian pharmaceutical industry was facing the recurring problem of phage contamination of probiotic fermentation batches. Adopting the approach of random mutagenesis, using UV light and MMS, several phage resistant strains were developed. The mutants were evaluated for retention /enhancement of their probiotic attributes, like aggregation potentials, tolerance to acids and bile salts, sporulation efficiencies etc. Genotypic and phenotypic variations and protein characterization was carried out for two mutants labelled as PIII and MIII. The observed phenotypi...

Objective: The present study was designed to evaluate the phytochemical composition and antioxida... more Objective: The present study was designed to evaluate the phytochemical composition and antioxidant activity of essential oil from Blumea eriantha DC collected from Seawoods, Navi Mumbai (Maharashtra, India). Methods: The essential oil was extracted by hydrodistillation using Clevenger type apparatus and subjected to GC-FID, GC-MS and HPTLC analysis. Furthermore antioxidant activity of essential oil was investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Results: Total 72 compounds were identified representing 96.83% of the oil. The main components of the essential oil are Ocim-(4E,6Z)-ene (13.72%), Caryophyllene (9.71%), Caryophyllene oxide (5.76%), Carvotanacetone (5.36%), Pinene (3.90%), Eudesmol (3.74%). HPTLC fingerprint of essential oil was also developed in order to carry out easy and fast identification of essential oil constituents. The oil showed activity as a radical scavenger at 437.92 ± 4.22 µg/ml. Conclusion: The present study describes the p...

In the current research work we have evaluated the antibacterial potential of essential oil of Bl... more In the current research work we have evaluated the antibacterial potential of essential oil of Blumea eriantha DC . The antimicrobial activity is studied against skin pathogens, mainly acne causing bacteria. The essential oil was extracted by hydrodistillation using Clevenger type apparatus. The oil showed significant antimicrobial activity against Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus and Streptococcus pyogenes. The antimicrobial activity was assessed by means of broth microdilution method and time kill analysis. The determined values of minimum inhibitory concentration and time kill analysis studies of the essential oil indicate that Streptococcus pyogenes is the most sensitive bacterium. The oil also showed significant activity against Propionibacterium acnes and Staphylococcus aureus . The obtained data highlight the potential of Blumea eriantha DC essential oil as a natural antibiotic in the treatment of skin infections.

Journal of Applied Biology & Biotechnology

Polyunsaturated Fatty Acids (PUFA) derived from fish exhibit beneficial physiological effects and... more Polyunsaturated Fatty Acids (PUFA) derived from fish exhibit beneficial physiological effects and have well-known nutritional and pharmaceutical significance and are commercially important as additives in food supplements. Microorganisms isolated from fish gut have been reported to be capable of producing PUFA. In our study 49 lipid producing microbes were isolated from intestines of various fresh water and salt water oily fish. The isolates were shortlisted following a preliminary screening scheme by studying a set of sequential parameters like intensity of lipid accumulation as judged by Sudan Black B staining, amount of biomass on nitrogen limited semi-synthetic medium, lipid quantity per gram biomass, relative quantities of saturated and unsaturated fatty acids and reproducibility of results. Ten shortlisted isolates were screened for PUFA production by Gas Chromatography after samples for GC analysis were prepared by extracting the lipids in organic solvent mixture followed by ...

Journal of BioScience and Biotechnology, 2016

Bacillus coagulans is a spore forming lactic acid bacterium. Spore forming bacteria, have been ex... more Bacillus coagulans is a spore forming lactic acid bacterium. Spore forming bacteria, have been extensively studied and commercialized as probiotics. Probiotics are produced by fermentation technology. There is a limitation to biomass produced by conventional modes of fermentation. With the great demand generated by range of probiotic products, biomass is becoming very valuable for several pharmaceutical, dairy and probiotic companies. Thus, there is a need to develop high cell density cultivation processes for enhanced biomass accumulation.The bioprocess development was carried out in 6.6l bench top lab scale fermentor. Four different cultivation strategies were employed to develop a bioprocess for higher growth and sporulation efficiencies of probiotic B. coagulans. Batch fermentation of B. coagulans yielded 18gl-1 biomass (as against 8.0gl-1 productivity in shake flask) with 60% spore efficiency. Fed batch fermentation was carried out for glucose, which yielded 25gl-1 of biomass. ...

Bacteriophages are the most notorious type of infection in the probiotic and dairy fermentations.... more Bacteriophages are the most notorious type of infection in the probiotic and dairy fermentations. Two phage resistant mutants viz. B. co PIII and B. co MIII ( B. coagulans mutants PIII and MIII) obtained in previous studies (Dubey and Vakil, 2010), were further characterized for their protein profile in comparison with the parental probiotic strain – B. coagulans . The cell lysates were subjected to ultra-centrifugation and the purified membrane fractions were resolved using 2D gel electrophoresis. The Isoelectric focussing showed 187, 202 and 154 protein spots for the parental strain, mutant B. co PIII and mutant B. co MIII, respectively. Ten and 18 protein spots were missing as compared to parent for mutants B.co PIII and B.co MIII whereas there were 21 and 14 new spots noticed for these two mutants. Eight membrane proteins present only in the phage sensitive parental culture could be tentatively identified by comparison with the complete proteome of B. coagulans by use of Uniprot...

Objective The present study was designed to develop a head space gas chromatography method using ... more Objective The present study was designed to develop a head space gas chromatography method using mass spectrometric detection for identification of essential oil constituents from Blumea eriantha DC in plasma. Methods The essential oil was extracted by hydrodistillation using Clevenger type apparatus. The rabbit plasma samples were spiked with essential oil and were further analyzed using dynamic head-space sampling with gas chromatography-mass spectrometry (GC-MS). R esults The analysis of plasma samples spiked with essential oil has revealed the selective absorption of some of the essential oil components. Conclusion Analytical method has been developed for identification of essential oil constituents in plasma which will be helpful in further in vivo pharmacokinetic studies of the essential oil. KEYWORDS Blumea eriantha DC, Dynamic Headspace Sampling, GC-MS, Plasma.

Indian Journal of Microbiology

Journal of Food: Microbiology, Safety & Hygiene

Food Chemistry

Aspergillus flavus is a filamentous fungus found in nature and characterized by the production of... more Aspergillus flavus is a filamentous fungus found in nature and characterized by the production of bright and colourful colonies. It grows on different substrates, producing secondary metabolites and, if present in foodstuffs, can be a source of health problems for humans and animals, as well as causing economic losses. Traditional methods for fungal identification are based on morphological characteristics, requiring specialists and being very time-consuming. The development of analytical alternatives might have advantages such as greater efficiency, more reproducibility and be less time-consuming. Thus, a qualitative analytical method to detect Aspergillus flavus in food samples, based on the identification of fungal chemical markers by HPLC-MS, was developed. The method comprises methanol extraction followed by HPLC-MS analysis, and was able to identify 14 fungus secondary metabolites, namely aflatoxin B1, aflatoxin G1, aspergillic acid, aspyrone, betaine, chrysogine, deacetyl parasiticolide A, flufuran, gregatin B, hydroxysydonic acid, nicotinic acid, phomaligin A, spinulosin and terrein.

SpringerPlus, 2016

Probiotics are microorganisms which when administered in adequate amounts confer health benefits ... more Probiotics are microorganisms which when administered in adequate amounts confer health benefits to the host. A leading pharmaceutical company producing Bacillus coagulans as a probiotic was facing the problem of recurring phage attacks. Two mutants viz. B. co PIII and B. co MIII that were isolated as phage resistant mutants after UV irradiation and MMS treatment of phage sensitive B. coagulans parental culture were characterized at functional and molecular level and were noted to have undergone interesting genetic changes. The non-specific genetic alterations induced by mutagenesis can also lead to alterations in cell performance. Hence, in the current study the parental strain and the two mutants were selected for shake flask optimization. Plackett-Burman design was used to select the significant culture variables affecting biomass production. Evolutionary operation method was applied for further optimization. The study showed wide variations in the nutritional requirements of pha...

International Journal of Current Microbiology and Applied Sciences, 2016

International Journal of Biotechnology for Wellness Industries, 2012

Biomedical & Pharmacology Journal, 2012

International Journal of pharma and Bio Science, 2017