Comparative genome-wide analysis of novel Streptomyces isolates RC1831 and RC1832: deciphering the role of functional carbohydrate (CAZy) active genes including chitinase for production of chitosan.

This work compares two bacterial isolates Streptomyces barkulensis RC1831 and Streptomyces chitinovorans RC1832 isolated from Chilika Lake sediments in Odisha, India, using whole-genome sequence analysis. According to the results of the genome analysis, the RC1831 genome has a chromosome with 6,383,258 bp (72.9% GC) and 6145 coding sequences and 66 RNA, while the RC1832 genome has a chromosome with 6,055,792 bp (73.1% GC) and 5824 coding sequences and 63 RNA. Further analysis of the carbohydrate active enzyme (CAZyme) revealed that RC1831 contains 78 glycoside hydrolase family genes, whereas RC1832 includes 50 glycoside hydrolases that have the potential to regulate the chitin-degrading enzymes. KAAS (KEGG Automatic Annotation Server) and AntiSMASH online tool V3.0.5 were used to identify a biosynthetic gene cluster in the isolated strain's genome. The detailed comparative analysis of the genes between the strains will help to gain better insight of chitin and other carbohydrate polymer degradation and secondary metabolite production in both the strains as well as the evolutionary relationship and possibilities of industrial application of these strains. Chitosan production might be explained by genes for the chitin breakdown pathway found in the genome sequence, but genes for later-stage conversion were not found. One significant biomolecule with a wide range of industrial uses is chitosan. Therefore, using these microbes to produce chitosan offers a viable waste disposal solution. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03936-5.

De novo assembly and comparative genome analysis for polyhydroxyalkanoates-producing Bacillus sp. BNPI-92 strain.

BACKGROUND: Certain Bacillus species play a vital role in polyhydroxyalkanoate (PHA) production. However, most of these isolates did not properly identify to species level when scientifically had been reported. RESULTS: From NGS analysis, 5719 genes were predicted in the de novo genome assembly. Based on genome annotation using RAST server, 5,527,513 bp sequences were predicted with 5679 bp number of protein-coding sequence. Its genome sequence contains 35.1% and 156 GC content and contigs, respectively. In RAST server analysis, subsystem (43%) and non-subsystem coverage (57%) were generated. Ortho Venn comparative genome analysis indicated that Bacillus sp. BNPI-92 shared 2930 gene cluster (core gene) with B. cereus ATCC 14579 T (AE016877), B. paranthracis Mn5T (MACE01000012), B. thuringiensis ATCC 10792 T (ACNF01000156), and B. antrics Amen T (AE016879) strains. For our strain, the maximum gene cluster (190) was shared with B. cereus ATCC 14579 T (AE016877). For Ortho Venn pair wise analysis, the maximum overlapping gene clusters thresholds have been detected between Bacillus s p.BNPI-92 and Ba. cereus ATCC 14579 T (5414). Average nucleotide identity (ANI) such as OriginalANI and OrthoANI, in silicon digital DND-DNA hybridization (isDDH), Type (Strain) Genome Server (TYGS), and Genome-Genome Distance Calculator (GGDC) were more essentially related Bacillus sp. BNPI-92 with B. cereus ATCC 14579 T strain. Therefore, based on the combination of RAST annotation, OrthoVenn server, ANI and isDDH result Bacillus sp.BNPI-92 strain was strongly confirmed to be a B. cereus type strain. It was designated as B. cereus BNPI-92 strain. In B. cereus BNPI-92 strain whole genome sequence, PHA biosynthesis encoding genes such as phaP, phaQ, phaR (PHA synthesis repressor phaR gene sequence), phaB/phbB, and phaC were predicted on the same operon. These gene clusters were designated as phaPQRBC. However, phaA was located on other operons. CONCLUSIONS: This newly obtained isolate was found to be new a strain based on comparative genomic analysis and it was also observed as a potential candidate for PHA biosynthesis.

Streptomyces griseoincarnatus strain RB7AG promotes Oryza sativa (var. swarna) growth under salt stress: mechanisms and potential applications.

The plant growth promoters (PGP) are the natural fertilizers that enhance the overall growth of the plant. We defined Streptomyces strain RB7AG as a potential halotolerant growth promoter and assessed its impact on rice plants' performance under salt stress. The organism was able to thrive at concentrations up to 10% of NaCl (w/v), optimal at 6% as measured by their cell growth, viability, and secondary metabolite production. Under salt stress, isolates were viable and generated Indolic chemicals and siderophores. The bacterized plants found to accumulate higher level of proline and antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalases (CAT) that are subjected to salt stress, particularly those treated with Streptomyces strain RB7AG, which helps the plants to thrive in the adverse condition. The Streptomyces-treated plants were also found to have increased roots and shoots length, implying a systemic tolerance mechanism. The strain's formulations were created utilizing five organic and inorganic wastes as the carrier medium, and the shelf life of the propagules was also tracked. Vermicompost and vermiculite formulations were found to have the highest viable bacteria after 3 months of storage period.

Effect of Statins on the Inflammatory Markers in Patients with Coronary Artery Disease.

Introduction Atherosclerosis mediated by inflammatory markers is the corner stone in the pathology of coronary artery disease (CAD). Hyperlipidemia, one of the risk factors is treated with statins. Statins also have a pleotropic role in reducing inflammation. Effect of statins on two inflammatory markers pentraxin 3(PTX 3) and high sensitivity C-reactive protein (hs-CRP) is explored in this study. Objective This article estimates the levels of serum PTX 3 and hs-CRP in CAD patients with and without statin therapy and correlates the levels with low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c) in CAD patients without statin therapy. Material and Methods This was a cross-sectional study conducted on 62 patients with CAD diagnosed by coronary angiogram. They were divided into two groups. Group I were the CAD patients on statin therapy and group II were CAD patients who never had any lipid lowering drugs irrespective of their lipid values. Serum PTX3, hs-CRP, and lipid profile were estimated in these groups. Comparison between the groups was done using Student's t -test and correlation analyzed using Pearson's correlation. Results Serum PTX 3 and hs-CRP levels were higher than the reference range in both the groups. But group I showed significantly low PTX 3 levels ( p -value = 0.032) compared with group II. There was a significant positive relationship between PTX 3 and LDL-c ( p = 0.003) in group II. Conclusion CAD patients on statin therapy have lower vessel wall inflammation compared with patients without statin therapy.

Whole genome sequencing of a novel chitinolytic Streptomyces sp. RB7AG reveals it's chitosan production potential: optimization of the process through Taguchi experimental design.

This study reports about the De novo whole genome sequencing and analysis of a bacterial isolate Streptomyces sp. Strain. RB7AG, isolated from the sediments of Chilika Lake, Odisha, India. The genome report in this paper highlights a size of 7,708,681 bp and a GC content of 72.3%. It also consists of 7274 coding sequence, 66 tRNA and 4 rRNA. Furthermore, carbohydrate active enzyme analysis revealed that the strain RB7AG has 127 glycoside hydrolase family genes, which is well known for hydrolysis of glycosidic bond in complex sugars. Thus, exploiting these microorganisms for the production of chitosan can be an appropriate waste disposal method of choice. Chitosan being an important biomolecule that has various industrial applications. Hence, the study also sought to improve the culture conditions for the Streptomyces sp. strain RB7AG for generation, recovery, and characterization of chitosan. Utilizing the isolate, various low-cost nitrogen sources, including peptone, yeast extract, ammonium chloride, urea along with pH, media, metal ions and surfactant were assessed for chitosan synthesis. In this context, traditional methods such as One Factor One Time are more time consuming and expensive too. The current work aims to establish a methodology to optimize the degradation of chitin by the chitinolytic Streptomyces sp. strain RB7AG, isolated from lake sediment for the production of chitosan. More than one factor was considered at the time of experiments, and the knowledge was integrated into Taguchi statistical design to determine the contribution of the most important factors required to achieve the desired end product i.e. chitosan. Highest chitosan production (2.188 µg/ml) was observed in MSM media, 1.0% NaCl (w/v), 0.5% Yeast extract, 1% Ca2+ and 0.1% Tween 80 at pH 9. The whole genome analysis of RB7AG would help in determining the mechanism involved in the breakdown activity. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03613-z.

l-Asparaginase producing novel Streptomyces sp. HB2AG: optimization of process parameters and whole genome sequence analysis.

l-asparaginase (ASNase) is a key enzyme widely used as an anti-cancer drug and is also used in the pharmaceutical and food processing industries. This enzyme's applications are determined by its source and nature. The production of the enzyme through the fermentation process is also crucial for economic feasibility. Searching for a new potent microbial strain is necessary for increased ASNase synthesis. In this work, a potent strain was isolated from the sediment of Chilika Lake and selected for its high ASNase production potential. It was recognized following Bergey's manual of determinative and phylogenetic analysis was carried out by 16S rDNA sequencing. The isolated organism was Streptomyces sp. HB2AG. Additionally, a genome-wide analysis of HB2AG was performed. The result showed that the HB2AG genome possesses a chromosome with 6,099,956 bp and GC content of 74.0%. The whole genome analysis of the strain HB2AG revealed the presence of ASNase (ansA, ansB) and Asparagine synthase (asnB) in the HB2AG genome. Optimization of media composition is crucial for microbial growth and obtaining the desired end product. The current effort focuses on the Taguchi orthogonal design to determine optimum factor combinations that would allow the strain to produce maximum ASNase enzyme. Results showed that compared to unoptimized media, approximately 1.76-fold higher ASNase production was observed in Sea Water Luria Bertani (SWLB) media, pH-5, 0.5% (w/v) of lactose, 0.5% (w/v) of casein, 2.5% (w/v) NaCl, 1 mM Ca2+ and 0.1% Tween 80. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03620-0.

Polyhydroxyalkanoate recovery from newly screened Bacillus sp. LPPI-18 using various methods of extraction from Loktak Lake sediment sample.

BACKGROUND: Nowadays, the conventional plastic wastes are very challenging to environments and its production cost also creates an economic crisis due to petrochemical-based plastic. In order to solve this problem, the current studies were aimed at screening and characterizing these polyhydroxyalkanoate (PHA)-producing isolates and evaluating the suitability of some carbon source for newly screened PHA-producing isolates. MATERIAL AND METHODS: Some carbon sources such as D-fructose, glucose, molasses, D-ribose and sucrose were evaluated for PHA production. Data were analyzed using SPSS version 20. The 16SrRNA gene sequence of these isolates was performed. These newly isolated taxa were related to Bacillus species. It was designated as Bacillus sp. LPPI-18 and affiliated Bacillus cereus ATCC 14577T (AE01687) (99.10%). Paenibacillus sp. 172 (AF273740.1) was used as an outgroup. RESULTS: Bacillus sp. LPPI-18 is a gram-positive, rod-shaped, endospore former, and citrate test positive. This isolate showed positive for amylase, catalase, pectinase, and protease test. They produced intracellular PHA granules when this isolate was stained with Sudan Black B (SBB) and Nile blue A (NBA) preliminary and specific staining dyes, respectively. Both temperature and pH used to affect polyhydroxyalkanoates (PHA) productivity. Bacteria are able to reserve PHA in the form of granules during stress conditions. This isolate produces only when supplied with carbon sources. More PHA contents (PCs) were obtained from glucose, molasses, and D-fructose. In this regard, the maximum mean value of PC was obtained from glucose (40.55±0.7%) and the minimum was obtained from D-ribose (12.4±1.4%). Great variations (P≤0.05) of PCs were observed among glucose and sucrose, molasses and sucrose, and D-fructose and sucrose carbon sources for PHA productivity (PP) of cell dry weight (CDW) g/L. After extraction, PHA film was produced for this typical isolate using glucose as a sole carbon source. Fourier transform infrared spectrum was performed for this isolate and showed the feature of polyester at 1719.64 to 1721.16 wavelengths for these extracted samples. The peak of fingerprinting (band of carboxylic acid group) at this wavelength is a characteristic feature of polyhydroxybutyrate (PHB) and corresponds to the ester functional group (C=O). CONCLUSION: In this study, newly identified Bacillus sp. LPPI-18 is found to be producing biodegradable polymers that are used to replace highly pollutant conventional plastic polymers. This isolate is also used to employ certain cost-effective carbon sources for the production of PHA polymers.

Exploration of genomic and functional features of chitinolytic bacterium Streptomyces chilikensis RC1830, isolated from Chilika Lake, India.

Streptomyces chilikensis RC1830 was previously isolated as a novel chitinolytic streptomycete from Chilika Lake, Odisha, India. The strain RC1830 is a representative member of the soil-dwelling, filamentous Streptomyces group that produces the majority of natural antibiotics and secondary metabolites. The objective of this work was to assess the chitin degradation ability and whole-genome sequence of Streptomyces chilikensis RC1830. TLC analysis of the fermentation product revealed that strain RC1830 can convert shrimp shell colloidal chitin to N-acetylated chitooligosaccharides (N-AcCOS). A genome-wide investigation of RC1830 was also carried out to investigate the genetic basis for chitin breakdown. The result showed that the RC1830 genome possesses a chromosome with 7,121,774 bp (73.2% GC). The genome consists of 6807 coding sequences, 69 tRNA, and 3 rRNA genes. Furthermore, carbohydrate-active enzyme (CAZyme) analysis revealed that RC1830 has 89 glycoside hydrolase family genes, which could modulate the enzymes involved in the degradation of chitin ultimately producing industrially important COS. The whole-genome information of RC1830 could emphasize the mechanism involved in the RC1830's chitin breakdown activity, endowing RC1830 with a promising alternative for COS production. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03184-5.

Hydoxylated ß- and δ-Hexacholorocyclohexane metabolites infer influential intrinsic atomic pathways interaction to elicit oxidative stress-induced apoptosis for bio-toxicity.

Hexachlorocyclohexane (HCH) has been recognized as an effective insecticide to protect crops against grasshoppers, cohort insects, rice insects, wireworms, and other agricultural pests and; for the control of vector-borne diseases such as malaria. It is a cyclic, saturated hydrocarbon, which primarily exists as five different stable isomers in the environment. Though the use of HCH is banned in most countries owing to its adverse effects on the environment, its metabolites still exist in soil and groundwater, because of its indiscriminate applications. In this study, a dose-dependent toxicity assay of the HCH isomers isolated from soil and water samples of different regions of Odisha, India was performed to assess the in vivo developmental effects and oxidative stress in zebrafish embryos. Toxicity analysis revealed a significant reduction in hatching and survivability rate along with morphological deformities (edema, tail malformations, spinal curvature) upon an increase in the concentration of HCH isomers; beta isomer exhibiting maximum toxicity (p < 0.05). Oxidative stress assay showed that ROS and apoptosis were highest in the fish exposed to ß-2 and δ-2 isomers of HCH in comparison to the untreated one. Zebrafish proved to be a useful biological model to assess the biological effects of HCH isomers. In addition, the results suggest the implementation of precautionary measures to control the use of organochlorine compounds that can lead to a decrease in the HCH isomers in the field for a healthier environment.

Association of Serum Pentraxin 3 and High-Sensitivity C-Reactive Protein with Severity of Coronary Stenosis.

Background: Atherosclerosis being the keystone in the pathology of coronary artery disease (CAD) is a chronic inflammation of arterial intima mediated by various inflammatory markers. Pentraxin 3 (PTX3) and high-sensitivity C-reactive protein (hs-CRP) are the two important biomarkers of chronic inflammation that causes atherosclerosis. Aims: This study aims to investigate the association of serum PTX3 and hs-CRP with the severity of coronary stenosis in patients undergoing coronary angiogram. Subjects and Methods: A total of 80 patients who underwent elective coronary angiogram were included. Their blood sample was collected for PTX3 and hs-CRP estimation prior to angiogram. Based on the angiogram, the participants were divided into four groups based on the number of arteries affected. PTX3 was estimated using enzyme-linked immunosorbent assay and hs-CRP was assayed using latex-enhanced immunosorbent assay. Statistical Analysis Used: Kruskal-Wallis test was used to find the association of PTX3 and hs-CRP in each group and Pearson's correlation was used to correlate PTX3 and hs-CRP with the extent of stenosis. Results: The mean PTX3 and hs-CRP levels in patients with some lesions in the coronary artery were 231.5 ± 129.9 pg/mL and 2.4 ± 0.4 mg/mL, respectively. The PTX3 levels elevate gradually with the severity of stenosis with P = 0.000 which is highly significant. A strong positive correlation was observed (R = 0.7929, P < 0.00001) with PTX3 and severity of stenosis. Whereas, for hs-CRP, the correlation was weaker (R = 0.3011, P = 0.006). Conclusions: PTX3 and hs-CRP can not only predict the number of arteries affected but also can differentiate between normal coronaries and CAD which can minimize the use of angiography.

Draft genome sequence and potential identification of a biosurfactant from Brevibacterium casei strain LS14 an isolate from fresh water Loktak Lake.

This study reports the whole-genome sequencing and sequence analysis of a bacterial isolate Brevibacterium casei strain LS14, isolated from Loktak Lake, Imphal, India. The de novo assembled genome reported in this paper featured a size of 3,809,532 bp, has GC content of 68% and contains 3602 genomic features, including 3551 protein-coding genes, 46 tRNA and 5rRNA. A biosurfactant biosynthesis gene cluster in the genome of the isolated strain was identified using AntiSMASH online tool V3.0.5 and KAAS (KEGG Automatic Annotation Server). The presence of biosurfactant was demonstrated by drop collapse, oil displacement and emulsification index. Subsequent chemical characterization using FTIR and LC-MS analyses revealed surfactin and terpene containing biosurfactant moieties. Also, the presence of genes involved in terpenoid synthesis pathway in the genome sequence may account for biosurfactant terpenoid backbone, but genes for later-stage conversion of terpenoid to biosurfactant were not ascertained. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02867-9.

Draft Genome Sequence of the Plant Growth-Promoting Rhizobacterium Klebsiella sp. Strain KBG6.2, Imparting Salt Tolerance to Rice.

Klebsiella sp. strain KBG6.2 is a potential salt-tolerant, plant growth-promoting rhizobacterium isolated from a rice field in Konark, Odisha, India. Here, we report the whole-genome sequencing of Klebsiella sp. strain KBG6.2, which has a 5.038-Mb genome containing 4,867 predicted protein-coding sequences and 79 RNA genes.

Optimization of the culture conditions for production of Polyhydroxyalkanoate and its characterization from a new Bacillus cereus sp. BNPI-92 strain, isolated from plastic waste dumping yard.

The aim of this study was to optimize the culture conditions for production, recovery and characterization of polyhydroxyalkanoate (PHA) from potential Bacillus cereus strain BNPI-92. Cost effective carbon sources such as crude oil (CO), rice bran (RB), sugar cane molasses (SCM) and wheat bran (WB) were evaluated for PHA production using the isolate. Higher cell dry weight (CDW) (g/L), PHA concentration (P conc.) (g/L) PHA contents (PC) (%) and PHA synthesis rate (PSR) were obtained from Glucose (60.67% w/v) as a carbon source at 37 °C and pH 7 using Taguchi DOE methods. The polymer was characterized by FTIR and its functional groups (C=O) (1719.41 cm-1 wavenumber) was a characteristic feature of PHB polymer. For 1HNMR, signals of methyne (CH) (5.28 ppm), methylene (-CH2-) (2.45 ppm) and methyl (CH3) (1.27 ppm) and copolymers were predicted. Copolymers such as P (3HB-co-3 HV) and P(3HB-co-3HHX) i.e. characteristic feature of PHB were obtained from a sample of glucose, WB, and RB, respectively. XRD pattern also confirmed the presence of PHA. The major compounds obtained from GC/MS analysis of the polymer recovered from the isolate BNP-92 were 2-butenoic acid, methyl ester (8.6%), ethyl cyclopropanecarboxylate (45.99%), 1-Undecanol (10.18%) which corresponds to and have produced from PHA after thermal degradation.

Rheinheimera pleomorphica sp. nov., a Novel Alkali-Tolerant Bacteria Isolated from Chilika Lake, India.

A novel Gram-negative gamma-proteobacterium, non-sporulating motile, rod or coccus-shaped bacterium designated as strain PKS7T was isolated from a sediment sample collected from Chilika Lake, Odisha, India and characterized taxonomically using a polyphasic approach. The major quinone was Q8 and major cellular fatty acids were C16:0, C17:0, C15:1w8c, C17:1w8c, C12:03-OH. The chemotaxonomic features confirmed the isolate to be a member of genus Rheinheimera. 16SrRNA gene sequence of strain PKS7T was closest in similarity to R. aquimaris SW-353T (99.36% identity), R. muenzenbergensis E49T (98.63%), R. nanhaiensis E407-8T (98.35%), R. japonica KMM 9513T (98.35%) and R. baltica DSM-14885T (98.08%). The 16S rRNA gene sequence-based phylogenetic analysis and sequence similarity between the isolated strain and type strains also revealed its affiliation to genus Rheinheimera. DNA-DNA relatedness with closest type strain R. aquimaris SW-353T was 25.0% (±3.40) and in silico DDH showed values in the range of 17.7-37.1% with the type strains of the genus Rheinheimera for which whole genome sequence are available. Strain PKS7T was also distinguished by a multi-locus sequence analysis (MLST) by alingning gyrB gene sequences of the closest type strains of Rheinheimera. The draft genome of strain PKS7T contained 32 contigs of total size 3,963,569 bp comprising of 3763 predicted coding sequences with a G + C content of 50.7 mol%. Comparision of phenotypic and genotypic data with its closest neighbours and closely related species confirm the strain PKS7T to be recognised as a novel species within the genus Rheinheimera, for which the name Rheinheimera pleomorphica sp. nov. is proposed. The type strain is PKS7T (= KCTC 42365 = JCM 30460).

An investigation for recovery of polyhydroxyalkanoates (PHA) from Bacillus sp. BPPI-14 and Bacillus sp. BPPI-19 isolated from plastic waste landfill.

Bio-plastic synthesis from renewable and cheap agro-based materials is a sustainable solution for replacing conventionally produced plastic with environmental contamination. The current study was aimed at screening and characterization of Polyhydroxyalkanoates (PHA) producing bacterial isolates, evaluation of their potential and recovery of PHA using the isolates. The PHA compounds were characterized using FT-IR. Based on 16SrRNA sequence analyses the isolates were designated as Bacillus sp. BPPI-14 and Bacillus sp. BPPI-19. The isolates were gram-positive, rod-shaped, endospore former, and citrate test positive. Intracellular PHA granules were observed when these isolates were stained with Sudan black B (SBB) and Nile blue A (NBA) preliminary and specific staining dyes, respectively. Effect of pH, temperature and carbon sources on the PHA production by the isolates BPPI-14 and BPPI-19 was studied. Maximum PHA production was recorded for Glucose (49.46±2.79%) by Bacillus sp. BPPI-14 and followed by molasses (45.86±2.17%) by Bacillus sp. BPPI-19, respectively at 37°C and pH7. The obtained PHA polymers were confirmed by preparation of plastic films for both the isolates. Fourier transform infrared spectrum for BPPI-14 and BPPI-19 showed the peak (carboxylic acid group) at 1706-1719.39cm-1 was a characteristic feature of PHA and corresponds functional group (C=O).

Optimization of media components for the production of N-acetylchitooligosaccharide from chitin by Streptomyces chilikensis through Taguchi experimental design.

Optimization of media composition for microbial growth is crucial particularly in industrial processes to obtain the desired end product. The waste from sea food industries includes the non-edible parts of shrimp, crabs and prawns which are rich in chitin as the major cause of pollution in coastal areas. Chitin degradation is carried out chemically. It can be degraded biologically also, particularly using microorganisms resulting in chitooligosaccahrides and the monomer N-acetylglucosamine. N-acetyl glucosamine and related chitooligosaccahrides have various applications such as treatment of cancer and metastasis, treatment of autoimmune reactions, as food supplements and increased plant stress tolerance against salinity and heavy metals. Thus, chitin waste can be efficiently degraded biologically using microorganisms to produce such useful products. Conventional methods such as One factor at a time (OFAT) are more time consuming and costly to address the problem. The current work focuses on the development of an experimental design to ascertain parameters optimized for chitin degradation by a Streptomyces chilikensis to produce various chitooligosaccharides. More than one factor was taken at a time to carry out the experiments and the data were fit into Taguchi Design to determine the contribution of the most important factors responsible for the production of the desired end product that is NAG and other chitooligosaccaharides. Highest NAG production (3741 µM/reaction) was observed in a media that contains 0.5% Raffinose (w/v), 0.5% peptone (w/v), 2.5% NaCl at pH 11.

A simple and rapid colorimetric method for the estimation of chitosan produced by microbial degradation of chitin waste.

Chitin is one of the most abundant biopolymers present in the environment. Chitosan being its major derivative can be obtained by hydrolysis of chitin, especially by microbial degradation. Estimation of resulting chitosan produced by chitin degradation is crucial to the process. Usefulness of the method of Badawy (Badawy, 2012) for estimation of chitosan is limited by interference resulting from susceptibility to variation in the pH of the sample and thiobarbituric acid. This work presents an improvement of the method proposed by Badawy for colorimetric determination of chitosan by using 3, 5-Dinitrosalicylic acid (DNSA) reagent instead of thiobarbituric acid, after one step depolymerization and deamination of chitosan with sodium nitrite (NaNO2). Eventually colorimetric estimation was carried out at 540 nm. With the use of DNSA reagent, the limitation of thiobarbituric acid are overcome. This method is easy, cost effective, and sensitive for quantitative determination of chitosan. This new improved method was applied for evaluation and quantification of chitosan produced by microbial degradation of chitin waste by different novel Streptomyces strains.

Purification and characterization of an extracellular thermo-alkali stable, metal tolerant chitinase from Streptomyces chilikensis RC1830 isolated from a brackish water lake sediment.

An extracellular thermo-alkali stable chitinase was obtained from Streptomyces chilikensis RC1830, a novel actinobacterial strain isolated from the sediments of Chilika lake, India. Purification of the enzyme was carried out by concentrating the enzyme with centrifugal device followed by chromatographic separation by DEAE Sepharose ion exchange resin.The molecular weight of the enzyme was 10.5 kDa as determined by SDS-PAGE. The optimum pH and temperature for the partially purified chitinase was pH 7 and 60 °C. The chitinase showed 40% activity at pH 11 after 24 h exposure at room temperature. The chitinase exhibited Km and Vmax values are 0.02 mM and 3.184 mol/min/mg of enzyme respectively. The 6 residue N-terminal sequence of the enzyme was not found similar to any of the reported chitinase enzyme. Based on the SDS PAGE, zymogram analysis, activity assays and other characteristics, it is proposed that the purified enzyme from S.chilikensis RC1830 is a chitinase.

Lipid Accumulation Product Index as Visceral Obesity Indicator in Psoriasis: A Case-control Study.

BACKGROUND: Psoriasis has well-known associations with individual components of metabolic syndrome such as hypertension, dyslipidemia, insulin resistance, and obesity. Traditional anthropometric measurements of obesity such as waist circumference (WC) and body mass index (BMI) do not differentiate between subcutaneous fat and visceral fat, the latter being associated with cardiovascular risk factors. Lipid accumulation product (LAP) index is a measure of visceral fat and has been found to be a better predictor of cardiovascular risk. However, LAP index has not been well-studied in psoriasis patients. AIMS AND OBJECTIVES: Our objective was to find out if LAP index differs significantly between psoriasis patients and controls and whether LAP index shows a correlation with duration and severity of psoriasis. MATERIALS AND METHODS: A case-control study was undertaken with 40 chronic plaque psoriasis patients and 42 controls. BMI and LAP index were calculated for all the patients and controls. Psoriasis area severity index (PASI) was calculated for all the psoriasis patients. Mann-Whitney U-test was done for comparing the age, BMI, WC, serum triglyceride, and LAP index between the cases and controls and to compare the LAP index between mild psoriasis and moderate-to-severe psoriasis groups. Spearman's correlation coefficient was used to assess the correlation of LAP index with duration of psoriasis and with PASI. Logistic regression models were done to assess the risk factors in psoriasis. RESULTS: A statistically significant difference was observed between the LAP index of controls (23.79 ± 13.02) and that of psoriasis patients (46.42 ± 27.2). LAP index was significantly higher in the moderate-to-severe psoriasis group as compared to the mild psoriasis group. LAP index was a significant risk factor associated with psoriasis (OR = 1.07; 95% CI: 1.03 - 1.11). CONCLUSION: Calculation of LAP index in psoriasis patients helps in identification of more individuals at high risk of cardiovascular morbidity than traditional anthropometric measurements of obesity.