Kinetics of dye decolorization using heterogeneous catalytic system with immobilized Achromobacter xylosoxidans DDB6.

Textile effluents containing toxic dyes must be treated effectively before discharge to prevent adverse environmental impacts. Traditional physical and chemical treatment methods are costly and generate secondary pollutants. In contrast, biological treatment is a more suitable, clean, versatile, eco-friendly, and cost-effective technique for treating textile effluent. It is well established that indigenous microbial populations present in effluents can effectively degrade toxic dyes. In this regard, Achromobacter xylosoxidans DDB6 was isolated from the effluent sample to decolorize crystal violet (CV), Coomassie brilliant blue (CBB), and alizarin red (AR) by 67.20%, 28.58%, and 20.41%, respectively. The growth parameters of A. xylosoxidans DDB6 in media supplemented with 100 ppm of various dyes were determined using the modified Gompertz growth model. The immobilized cells in calcium alginate beads showed apparent decolorization rate constant of 0.27, 0.18, and 0.13 h-1 for CV, CBB, and AR, respectively. The immobilized cells in a packed bed reactor with an optimum flow rate of 0.5 mL/min were used to treat 100 ppm of CV with a percentage decolorization of 79.47% after three cycles. Based on the findings, A. xylosoxidans DDB6 could be effectively used for decolorization of various dyes.

Draft Genome Sequence of Aeromonas dhakensis Strain F2S2-1, Isolated from the Skin Surface of an Indian Oil Sardine (Sardinella longiceps).

Draft genome sequencing of Aeromonas dhakensis strain F2S2-1, isolated from the skin surface of an Indian oil sardine (Sardinella longiceps), has been carried out. The draft genome was roughly 4.7 Mb in size with 61.7% G+C content. Annotation of the genome yielded 4,337 genes coding for proteins, tRNAs, and rRNAs. Annotation also revealed the presence of 52 genes linked to resistance to antibiotics/toxic compounds. Pathway analysis revealed the presence of novobiocin biosynthetic genes and genes for biosynthesis of a siderophore group on nonsynthetic peptides.

Genetic Diversity among Yersinia enterocolitica Isolated from Chicken and Fish in and around Coimbatore City, India.

BACKGROUND: Yersinia enterocolitica is rapidly emerging worldwide as an enteric pathogen and has become a major cause of diarrhea even in developed countries. The aim of this study was to characterize and genetic diversity analysis among Y. enterocolitica strains isolated from fish and chicken sources. METHODS: From 44 strains, 55% (24 strains) found to be positive for Y. enterocolitica by colony morphology, biochemical tests and 16S rRNA. We investigate the diversity of Y. enterocolitica by hemolytic activity, antimicrobial resistance, RAPD, ERIC and REP-PCRs PCR, profiling of outermembrane proteins and lipopolysaccarides. RESULTS: Forty one percent of the strains were found to be the producers of haemolysin at 37 °C but not at 28 °C. All the isolates were exhibiting multi-drug resistance and found sensitive to chloramphenicol, and resistant to ciprofloxacin and amoxicillin. Eight, eleven and twelve different genotypic patterns were observed in RAPD, ERIC and REP-PCRs respectively. Five isolates have produced high molecular weight protein (HMWP) with a molecular weight of 150 - 220 kDa. Mostly LPS produce identical profiles, 22 strains have produced smooth LPS, while 2 strains have produced the rough LPS pattern. CONCLUSION: Genotyping tools strongly confirm the co-existence wide genetic diversity among the strains tested. By using any or the combination of these molecular tools, epidemiological investigation on Y. enterocolitica could be elucidated effectively. These results showed that the REP-PCR is more informative and discriminative than other for analysis of Y. enterocolitica diversity.

Occurrence of Aeromonas hydrophila in acute gasteroenteritis among children.

BACKGROUND & OBJECTIVE: The interest on the occurrence multidrug resistance and pathogenicity of Aeromonas hydrophila is increasing worldwide since it causes gasteroenteritis to children. Though reports on the occurrence of gasteroenteritis among children due to A. hydrophila in Tamil Nadu are available from certain areas, no information is available from Coimbatore. Hence, this study was undertaken to find out the occurrence of the pathogenic A. hydrophila in diarrhoeal stool of children, particularly in Coimbatore region. METHODS: Isolation and identification of A. hydrophila was carried out from stool samples collected from children with acute diarrhoea. Multiple antibiotic resistance was determined by disc diffusion method. The pathogenicity of A. hydrophila was confirmed by production of haemolysin, protease and slime. RESULTS: Of the 216 samples, 21 (9.7%) were positive for A. hydrophila. Among them 20 isolates were resistant to bacitracin. Most of the isolates showed multiple antibiotic resistance. Among the 21 isolates, protease and haemolysin producers were 100 and 95 per cent respectively. About 76 per cent of the isolates produced slime. INTERPRETATION & CONCLUSION: The results of the present study indicated the presence of pathogenic A. hydrophila in the study area causing diarrhoea among children.