Purification and characterization of chitinase from Alcaligenes faecalis AU02 by utilizing marine wastes and its antioxidant activity

Marine waste is an abundant renewable source for the recovery of several value added metabolites with potential industrial applications. This study describes the production of chitinase on marine waste, with the subsequent use of the same marine waste for the extraction of antioxidants. A chitinase-producing bacterium isolated from seafood effluent was identified as Alcaligenes faecalis AU02. Optimal chitinase production was obtained in culture conditions of 37°C for 72 h in 100 ml medium containing 1% shrimp and crab shell powder (1:1) (w/v), 0.1% K2HPO4, and 0.05% MgSO4·7H2O. The molecular weight of chitinase was determined by SDS-PAGE to be 36 kDa. The optimum pH, temperature, pH stability, and thermal stability of chitinase were about 8, 37°C, 5–12, and 40–80°C, respectively. The antioxidant activity of A. faecalis AU02 culture supernatant was determined through scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) as 84%, and the antioxidant compound was characterized by TLC and its FT-IR spectrum. The present study proposed that marine wastes can be utilized to generate a high-value-added product and that pharmacological studies can extend its use to the field of medicine

Rubber Clay Nanocomposites

The use of nanofillers allows the development of nanocomposites with improved properties and novel applications. The technological goal is possible due to the new compounding method that allows a particle dispersion in the nanometer scale increasing the specific surface area.Fil: Cova Sánchez, Mariajose. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Bacigalupe, Alejandro. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; ArgentinaFil: Escobar, Mariano Martin. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mansilla, Marcela Angela. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Characterization of an extracellular lipase and its chaperone from Ralstonia eutropha H16

Lipase enzymes catalyze the reversible hydrolysis of triacylglycerol to fatty acids and glycerol at the lipid–water interface. The metabolically versatile Ralstonia eutropha strain H16 is capable of utilizing various molecules containing long carbon chains such as plant oil, organic acids, or Tween as its sole carbon source for growth. Global gene expression analysis revealed an upregulation of two putative lipase genes during growth on trioleate. Through analysis of growth and activity using strains with gene deletions and complementations, the extracellular lipase (encoded by the lipA gene, locus tag H16_A1322) and lipase-specific chaperone (encoded by the lipB gene, locus tag H16_A1323) produced by R. eutropha H16 was identified. Increase in gene dosage of lipA not only resulted in an increase of the extracellular lipase activity, but also reduced the lag phase during growth on palm oil. LipA is a non-specific lipase that can completely hydrolyze triacylglycerol into its corresponding free fatty acids and glycerol. Although LipA is active over a temperature range from 10 °C to 70 °C, it exhibited optimal activity at 50 °C. While R. eutropha H16 prefers a growth pH of 6.8, its extracellular lipase LipA is most active between pH 7 and 8. Cofactors are not required for lipase activity; however, EDTA and EGTA inhibited LipA activity by 83 %. Metal ions Mg[superscript 2+], Ca[superscript 2+], and Mn[superscript 2+] were found to stimulate LipA activity and relieve chelator inhibition. Certain detergents are found to improve solubility of the lipid substrate or increase lipase-lipid aggregation, as a result SDS and Triton X-100 were able to increase lipase activity by 20 % to 500 %. R. eutropha extracellular LipA activity can be hyper-increased, making the overexpression strain a potential candidate for commercial lipase production or in fermentations using plant oils as the sole carbon source.Malaysia-MIT Biotechnology Partnership Programm

Chitin degrading potential of bacteria from extreme and moderate environment

248-254<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">Five hundred chitin-degrading bacteria were isolated from 20 different locations. High percentage of potent chitin degraders was obtained from po lluted regions. Potent chitin- degrading bacteria were selected by primary and seondary screening. Among the selected isolates 78% were represented by the genus Streptomyces. Majority of the isolates had good chitinolysis relative to the growth although isolates with better growth were also seen. Such isolates are important for the production of SCP from chitinous wastes. The potent iso lates belonged to the genera Streptomyces, Kitasatosporia, Saccharopolyspora, Nocardioides, Nocardiopsis, Herbidospora, Micromonospora, Microbispora, ,Actinoplanes, Serratia, Bacillus and Pseudomonas. This study forms a comprehensive base for the study of diversity of chitinolytic systems of  bacteria.</span

<span style="font-size:11.0pt;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;letter-spacing:-.1pt;mso-ansi-language:EN-GB;mso-fareast-language:EN-US; mso-bidi-language:HI" lang="EN-GB">Comparative studies on ability of <i style="mso-bidi-font-style: normal">N</i>-acetylated chitooligosaccharides to scaven<span style="font-size:11.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:Mangal; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">ge reactive oxygen species and protect DNA from oxidative damage</span></span>

186-192<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Antioxidants have key role in scavenging free radicals and have been considered as dietary part of health conscious population for reducing the risk of many diseases. In the present study, commercially available N-acetylated chitooligosaccharides [(GlcNAc)n; n=2, 3, 5, 6] were studied for their antioxidant ability against superoxide, hydroxyl, DPPH radicals and H2O2 by various radical scavenging assays. The N-acetylated chitooligosaccharides exhibited radical scavenging activities in the range of 49.1-63% for hydroxyl radical and 41-53.3% for superoxide radical. Their antioxidant ability was at par or better than standard antioxidants like butylated hydroxyanisole and mannitol. These <i style="mso-bidi-font-style: normal">N-acetylated chitooligosaccharides were also evaluated for their ability to prevent oxidative DNA damage in peripheral blood mononuclear cells exposed to H2O2. (GlcNAc)2, (GlcNAc)3, (GlcNAc)5 and (GlcNAc)6 decreased the oxidative DNA damage due to H2O2 by 59.5, 55.5, 22.9 and 4.9%, respectively. This antioxidative potential of <i style="mso-bidi-font-style: normal">N-acetylated chitooligosaccharides can be extended to beneficial health applications.</span

Molecular typing of antibiotic resistant bacteria isolated and identified as ESBL producers from polluted water reservoirs

Anthropogenic polluted reservoirs are the mating hub for antibiotic resistant genes and multidrug resistant bacteria (MDR). The rapid emergence of this MDR is the consequence of mutations in the genes as well as the horizontal gene transfer of mobile elements carrying the resistant genes. Current study focuses on isolation and characterization of Extended spectrum β-lactamase (ESBL) producers from diverse water resources of Pune city and to understand the genetic modifications responsible for multidrug resistance using whole genome sequencing (Next Generation sequencing-Illumina sequencing). The identified isolates were Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae and Stenotrophomonas maltophilia. Mechanism of resistance developed by all isolates was efflux pump as per the genes (adeL, macA, macB, ros B) identified by Comprehensive Antibiotic Resistance Database. Primary phenotypic detection of isolates as ESBL producers and AmpC hyper producers was supportive as identified genes were resistant to all antibiotics including last resorts like carbapenems, peptide antibiotics. Rapid emergence of antibiotic resistance was seen in one isolate due to presence of additional 19 antibiotic resistant genes (blaI, exo bet lactamase, PDC 9, CMY-83, mec I, etc.). The investigation alarms the deadly pollution of reservoirs due to haphazard use of antibiotics which pressurizes rapid emergence and persistence of MDR

Potential<i style="mso-bidi-font-style: normal"> </i>of <i style="mso-bidi-font-style:normal">Microbispora </i><span style="mso-bidi-font-style:italic">sp. V2 as biocontrol agent against <i style="mso-bidi-font-style:normal">Sclerotium rolfsii, </i>the causative agent of<i style="mso-bidi-font-style:normal"> </i>southern blight of <i style="mso-bidi-font-style:normal">Zea mays </i>L<i style="mso-bidi-font-style:normal"> </i>(Baby corn)–<i style="mso-bidi-font-style: normal">in vitro</i> studies </span>

1147-1151The study was undertaken with the aim of exploring novel and beneficial agro activities of rare actinomycetes like <i style="mso-bidi-font-style: normal">Microbispora sp. V2. The antagonistic activity of Microbispora sp. V2 was evaluated as a biocontrol agents against Sclerotium rolfsii, a soil-borne fungal plant pathogen. The methodology performed for evaluation of biocontrol agent was in vitro evaluation assay which comprised of three tests viz., cellophane overlay technique, seed germination test and Thiram (fungicide) tolerance of Microbispora <span style="mso-bidi-font-style: italic">sp. V2. The isolate was found to inhibit the fungal pathogen Sclerotium rolfsii to 91.43% in cellophane assay. In seed germination assay, <i style="mso-bidi-font-style: normal">Microbispora sp. V2 treated seeds resulted in 25.75% increased germination efficiency, as compared to seeds infected by Sclerotium rolfsii. The isolate Microbispora sp. V2 could tolerate 1000 µg mL-1 of Thiram (fungicide). The in vitro assay studies proved that Microbispora sp. V2 can be used as antifungal antagonist and thus posses’ great potential as biocontrol agent against southern blight caused by Sclerotium rolfsii in Zea mays L (Baby corn) which causes large economical losses. </span