Utilization of tannery solid waste for protease production by Synergistes sp. in solid‐state fermentation and partial protease characterization

Synergistes sp. DQ560074 produced a protease in submerged fermentation (SmF) at 400–420 U/mL and in solid‐state fermentation (SSF) at 745–755 U/g. The protease, which belongs to the aspartic protease class, was active over a wide range of pH (5–7) and at high temperatures (25–45°C). The protease is stable and active in various polar protic solvents (50% v/v) like ethanol, isopropanol, n–butanol, in polar aprotic solvents (50% v/v) like acetonitrile, and in non‐polar solvents (50% v/v) such as ethylacetate and toluene, but not in hydrophilic organic solvents (methyl alcohol and acetone). As far as we know, this is the first contribution to the production of a mesophilic protease with solvent stability in SSF using a proteinaceous solid waste.     

Bio-composite scaffolds containing chitosan/nano-hydroxyapatite/nano-copper-zinc for bone tissue engineering

The current study involves fabrication and characterization of bio-composite scaffolds containing chitosan (CS), nano-hydroxyapatite (nHAp) and Cu-Zn alloy nanoparticles (nCu-Zn) by freeze drying technique. The fabricated composite scaffolds (CS/nHAp and CS/nHAp/nCu-Zn) were characterized by SEM, EDX, XRD and FT-IR studies. The addition of nCu-Zn in the CS/nHAp scaffolds significantly increased swelling, decreased degradation, increased protein adsorption, and increased antibacterial activity. The CS/nHAp/nCu-Zn scaffolds had no toxicity towards rat osteoprogenitor cells. So the developed CS/nHAp/nCu-Zn scaffolds have advantageous and potential applications over the CS-nHAp scaffolds for bone tissue engineering.     

Chitosan scaffolds containing silicon dioxide and zirconia nano particles for bone tissue engineering

A scaffold harboring the desired features such as biodegradation, biocompatibility, porous structure could serve as template for bone tissue engineering. In the present study, chitosan (CS), nano-scaled silicon dioxide (Si) and zirconia (Zr) were combined by freeze drying technique to fabricate a bio-composite scaffold. The bio-composite scaffold (CS/Si/Zr) was characterized by SEM, XRD and FT-IR studies. The scaffold possessed a porous nature with pore dimensions suitable for cell infiltration and colonization. The presence of zirconia in the CS/Si/Zr scaffold decreased swelling and increased biodegradation, protein adsorption and bio-mineralization properties. The CS/Si/Zr scaffold was also found to be non-toxic to rat osteoprogenitor cells. Thus, we suggest that CS/Si/Zr bio-composite scaffold is a potential candidate to be used for bone tissue engineering.     

IGF2BP2 Alternative Variants Associated with Glutamic Acid Decarboxylase Antibodies Negative Diabetes in Malaysian Subjects

Background

The association of Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) common variants (rs4402960 and rs1470579) with type 2 diabetes (T2D) has been performed in different populations. The aim of this study was to evaluate the association of alternative variants of IGF2BP2; rs6777038, rs16860234 and rs7651090 with glutamic acid decarboxylase antibodies (GADA) negative diabetes in Malaysian Subjects.

Methods/Principal Findings

IGF2BP2; rs6777038, rs16860234 and rs7651090 single nucleotide polymorphisms (SNPs) were genotyped in 1107 GADA negative diabetic patients and 620 control subjects of Asian from Malaysia. The additive genetic model adjusted for age, race, gender and BMI showed that alternative variants; rs6777038, rs16860234 and rs7651090 of IGF2BP2 associated with GADA negative diabetes (OR = 1.21; 1.36; 1.35, P = 0.03; 0.0004; 0.0002, respectively). In addition, the CCG haplotype and diplotype CCG-TCG increased the risk of diabetes (OR = 1.51, P = 0.01; OR = 2.36, P = 0.009, respectively).

Conclusions/Significance

IGF2BP2 alternative variants were associated with GADA negative diabetes. The IGF2BP2 haplotypes and diplotypes increased the risk of diabetes in Malaysian subject.     

Rapid detection of ESBL-producing Klebsiella pneumoniae in blood cultures by fluorescent in-situ hybridization

Multi-resistant Enterobacteriaceae pose a serious threat of hospital acquired infections and their rapid identification is important for better clinical outcome. This study describes the rapid identification of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae of the sulphydryl variable-type by fluorescent in-situ hybridization. The method which rapidly identifies the target genes within 1 h could be a potentially rapid bacterial diagnostic tool.     

Purification of extracellular acid protease and analysis of fermentation metabolites by Synergistes sp. utilizing proteinaceous solid waste from tanneries

The untanned proteinaceous tannery solid waste, animal fleshing (ANFL), was used as a substrate for acid protease production by Synergistes sp. The strain was isolated from an anaerobic digester used for the treatment of tannery solid waste and was selected for its enhanced protease production at activity 350-420 U/ml. The optimum pH was in the acidic range of 5.5-6.5 and optimum temperature was in mesophilic range of 25-35 degrees C. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the zymogram analyses of the purified protein indicated an estimated molecular mass of 60 kDa. This protease could be classified as aspartic protease based on its inhibition by aspartate type protease inhibitor pepstatin and on non-inhibition by 1,10-phenanthroline, EDTA, EGTA and phenylmethylsulfonyl fluoride. The degradation of ANFL was confirmed by Gas Chromatography-Mass Spectroscopy (GC-MS), Proton Nuclear Magnetic Resonance Spectroscopy (H1 NMR) and Scanning Electron Microscopy (SEM) analyses. In this study we found that the activity of acid protease depended on factors such as calcium concentration, pH and temperature. Based on these lines of evidence, we postulate that this protease is a highly catalytic novel protease of its type.