Papers by Sathi Reddy Koppula
Environmental Sustainability
The present study was primarily emphasized on isolation of yeast from diverse samples and screeni... more The present study was primarily emphasized on isolation of yeast from diverse samples and screening for potential biosurfactant producer. Yeast isolates AH16, AH23, AH46 and AH62 showed effective oil displacement activity and were confirmed to be potential biosurfactant producers. Among them, maximum yield of 4.23 g/l of crude biosurfactant was extracted from isolate AH62 within 96 h of fermentation which also showed effective emulsification activity of 76.4 ± 0.38% when tested against diesel. It could further decrease the surface tension of water from 72 to 31.4 ± 0.38 mN/m and was hence selected for subsequent study. The isolate was identified as Candida sp. AH62 through phylogenetic analysis. Characterization of extracted biosurfactant using thin layer chromatography (TLC), Fourier transform infrared spectroscopy (FTIR), high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed sophorolipid to exist as a heterogeneous mixture of lactonic and acidic forms. The isolated sophorolipids showed potential antibacterial activity towards pathogenic Gram negative and Gram positive bacteria.
Bioresource Technology, 2016
Mango kernel oil (MKO), derived from mango kernels, considered to be one of the highly generated ... more Mango kernel oil (MKO), derived from mango kernels, considered to be one of the highly generated agro-industrial waste, is assessed for its use as substrate for sustainable production of rhamnolipids. In the present study, MKO in combination with glucose gave maximum rhamnolipid yield of 2.8g/l which reduced the surface tension of water from 72 to 30mN/m, holding a CMC of 80mg/l and also showed high emulsification activity (73%) with diesel. Cell free broth was found to be stable even at high temperature (autoclaved at 121°C for 30min), pH value (up to pH 12) and salinity (up to 20% NaCl). The LC-MS data showed mono-rhamnolipid to be predominant congener followed by di-rhamnolipid in presence of MKO. Whereas, di-rhamnolipid was abundant when a combination of MKO with glucose was used. The produced rhamnolipid mixture showed good antifungal activity against various phytopathogens.
Standards in genomic sciences, Jan 15, 2014
Bacillus amyloliquefaciens HB-26, a Gram-positive bacterium was isolated from soil in China. SDS-... more Bacillus amyloliquefaciens HB-26, a Gram-positive bacterium was isolated from soil in China. SDS-PAGE analysis showed this strain secreted six major protein bands of 65, 60, 55, 34, 25 and 20 kDa. A bioassay of this strain reveals that it shows specific activity against P. brassicae and nematode. Here we describe the features of this organism, together with the draft genome sequence and annotation. The 3,989,358 bp long genome (39 contigs) contains 4,001 protein-coding genes and 80 RNA genes.
Bioresource technology, Jan 15, 2017
An effecient feather-degrading bacterium was isolated from poultry dumping yard and identified as... more An effecient feather-degrading bacterium was isolated from poultry dumping yard and identified as Bacillus pumilus GRK based on 16S rRNA sequencing. Complete feather degradation (98.3±1.52%) with high keratinase production (373±4 U/ml) was observed in 24h under optimized conditions (substrate 1% (w/w); inoculum size 4% (v/v); pH 10; 200rpm at 37°C) with feathers as sole carbon and nitrogen source in tap water. The fermented broth was enriched with amino acids like tryptophan (221.44µg/ml), isoleucine (15.0µg/ml), lysine (10.81µg/ml) and methionine (7.24µg/ml) suggesting its potential use as feed supplement. The keratinase produced was a detergent stable serine protease and its activity was further enhanced by Ca(+2) and Mg(+2). Bacillus pumilus GRK keratinase was successfully utilised as bioadditive in detergent formulations for removing the blood stains from cloth without affecting its fiber and texture.
Bacillus amyloliquefaciens strain RHNK22 isolated from groundnut rhizosphere showed direct and in... more Bacillus amyloliquefaciens strain RHNK22 isolated from groundnut rhizosphere showed direct and indirect plant growth-promoting traits along with biosurfactant activity and reduction in surface tension of water. Biosurfactants were identified as lipopeptides (surfactin, iturin, and fengycin) by molecular and biochemical analysis in our studies. B acillus amyloliquefaciens strain RHNK22 was isolated from groundnut by the enrichment culture method as described by Dubey and Juwarkar (1). B. amyloliquefaciens RHNK22 has been used to produce industrially important biosurfactants with surface tension reduction and antifungal activity (2), plant growth-promoting traits, and antioxidant and probiotic properties (un-published data) and was thus subjected to genomic sequencing. The shotgun sequencing of Bacillus amyloliquefaciens strain RHNK22 genome was performed using a paired-end (PE) 2 ϫ 150 bp library on the Illumina platform (NextSeq 500). The draft genome, as submitted to GenBank, was 3,978,182 bp in length with a mean scaffold size of 1,037,178 bp, a median size of 48,109 bp, and a maximum length of 987,166 bp. The mean GϩC content of the genome was found to be 46.02% using the Velvet de novo assembler (3). Coding DNA sequence (CDS) prediction was performed using Prodigal v2.60. A total of 3,872 CDS were identified from the B. amyloliquefaciens strain RHNK22 assembly. BLASTx analysis was performed using NCBI BLASTϩ to search 3,872 CDS against the nonredundant (NR) database. A significant E value of 10 Ϫ5 was used as a filter to retain significant BLAST hits and remove short ambiguous alignments. The top BLAST result distributions were obtained by calculating the total number of CDS for each reported species (4). A total of 3,872 CDS were annotated with NCBI BLAST. A total of 3,611 out of 3,872 CDS represent homologs in B. amyloliquefaciens. B. amy-loliquefaciens sp. plantarum CAUB946 is the most predominant strain among B. amyloliquefaciens species in the BLAST result which is used for single nucleotide polymorphism (SNP) analysis. SNP discovery was carried out using the draft genome identified through BLAST. The reads of the samples were mapped on the reference genome (NC_016784) using Bowtie 2. A total of 16,264 SNP were identified after filtration for a read depth of 10 and quality score of 20. The quality filtered SNP were filtered for indels (5). A total of 15,701 SNP were identified after indel filtration with 89.99%overall rapid mapping. Subsequently, SNP were discarded by taking a flanking distance of 100 bp and we obtained 7,986 SNP. Gene ontology (GO) assignments were performed to classify the functions of the CDS based on gene ontology terms (6). GO mapping will provide the ontology of defined terms representing gene product properties which are grouped into three main domains: biological process, molecular function, and cellular component. The GO mapping was performed using the BLAST2GO program using a genus database generated from B. amyloliquefa-ciens sp. genomes, B. amyloliquefaciens sp. plantarum CAUB946 (GenBank accession number NC_016784), B. amyloliquefaciens FZB42 (GenBank accession number NC_009725), and B. amy-loliquefaciens plantarum UCMB 5036 (GenBank accession number NC_020410). The GO annotation results of B. amyloliquefa-ciens strain RHNK22 were classified into 2,456 molecular function GO-terms, 2,572 GO-terms classified as biological processes, and 1,063 GO-terms in the cellular component category. The tRNA scan SE program was used to predict the 79 t-RNA in B. amyloliquefaciens strain RHNK22. A total of 5 r-RNA were identified in the B. amyloliq-uefaciens strain RHNK 22 sample using the RNAmmer 1.2 server. Nucleotide sequence accession number. This whole-genome shotgun project has been deposited in NCBI GenBank under the accession number LMAG00000000. ACKNOWLEDGMENTS
An effecient feather-degrading bacterium was isolated from poultry dumping yard and identified as... more An effecient feather-degrading bacterium was isolated from poultry dumping yard and identified as Bacillus pumilus GRK based on 16S rRNA sequencing. Complete feather degradation (98.3 ± 1.52%) with high keratinase production (373 ± 4 U/ml) was observed in 24 h under optimized conditions (substrate 1% (w/w); inoculum size 4% (v/v); pH 10; 200 rpm at 37 °C) with feathers as sole carbon and nitrogen source in tap water. The fermented broth was enriched with amino acids like tryptophan (221.44 µg/ml ), isoleucine (15.0 µg/ml), lysine (10.81 µg/ml) and methionine (7.24 µg/ml) suggesting its potential use as feed supplement. The keratinase produced was a detergent stable serine protease and its activity was further enhanced by Ca +2 and Mg +2 . Bacillus pumilus GRK keratinase was successfully utilised as bioadditive in detergent formulations for removing the blood stains from cloth without affecting its fibre and texture.
The present study was primarily emphasized on isolation of yeast from diverse samples and screeni... more The present study was primarily emphasized on isolation of yeast from diverse samples and screening for potential biosur-factant producer. Yeast isolates AH16, AH23, AH46 and AH62 showed effective oil displacement activity and were confirmed to be potential biosurfactant producers. Among them, maximum yield of 4.23 g/l of crude biosurfactant was extracted from isolate AH62 within 96 h of fermentation which also showed effective emulsification activity of 76.4 ± 0.38% when tested against diesel. It could further decrease the surface tension of water from 72 to 31.4 ± 0.38 mN/m and was hence selected for subsequent study. The isolate was identified as Candida sp. AH62 through phylogenetic analysis. Characterization of extracted biosurfactant using thin layer chromatography (TLC), Fourier transform infrared spectroscopy (FTIR), high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed sophorolipid to exist as a heterogeneous mixture of lactonic and acidic forms. The isolated sophorolip-ids showed potential antibacterial activity towards pathogenic Gram negative and Gram positive bacteria.
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Papers by Sathi Reddy Koppula