Ibrar Khan

High-level production of calcium malate from glucose by Penicillium sclerotiorum K302.

In this study, after screening of 9 fungal strains for their ability to produce calcium malate, it was found that Penicillium sclerotiorum K302 among them could produce high-level of calcium malate. Under the optimal conditions, the titer of calcium malate in the supernatant was 88.6 g/l at flask level. During 10-l fermentation, the titer of 92.0 g/l, the yield of 0.88 g/g of glucose and the productivity of 1.23 g/l/h were reached within 72 h of the fermentation, demonstrating that the titer, yield and productivity of calcium malate by this strain were very high and the fermentation period was very short. After analysis of the partially purified product with HPLC, it was found that the main product was calcium malate. The results showed that P. sclerotiorum K302 obtained in this study was suitable for developing a novel one-step fermentation process for calcium malate production from glucose on large scale.

Chaetomium endophytes: a repository of pharmacologically active metabolites

Fungal endophytes are group of fungi that grow within the plant tissues without causing immediate signs of disease and are abundant and diverse producers of bioactive secondary metabolites. The Chaetomium genus of kingdom fungi is considered to be a rich source of unique bioactive metabolites. These metabolites belong to chemically diverse classes, i.e., chaetoglobosins, xanthones, anthraquinones, chromones, depsidones, terpenoids and steroids. Cheatomium through production of diverse metabolites can be considered as a potential source of antitumor, cytotoxic, antimalarial, antibiotic and enzyme inhibitory lead molecules for drug discovery. This review covers isolation of Cheatomium endophytes, extraction and isolation of metabolites and their biological activities.

Molecular cloning and sequence analysis of a PVGOX gene encoding glucose oxidase in Penicillium viticola F1 strain and it\'s expression quantitation

The PVGOX gene (accession number: KT452630) was isolated from genomic DNA of the marine fungi Penicillium viticola F1 by Genome Walking and their expression analysis was done by Fluorescent RT-PCR. An open reading frame of 1806bp encoding a 601 amino acid protein (isoelectric point: 5.01) with a calculated molecular weight of 65,535.4 was characterized. The deduced protein showed 75%, 71%, 69% and 64% identity to those deduced from the glucose oxidase (GOX) genes from different fungal strains including; Talaromyces variabilis, Beauveria bassiana, Aspergillus terreus, and Aspergillus niger, respectively. The promoter of the gene (intronless) had two TATA boxes around the base pair number -88 and -94 and as well as a CAAT box at -100. However, the terminator of the PVGOX gene does not contain any polyadenylation site (AATAAA). The protein deduced from the PVGOX gene had a signal peptide containing 17 amino acids, three cysteine residues and six potential N-linked glycosylation sites, among them, -N-K-T-Y- at 41 amino acid, -N-R-S-L- at 113 amino acid, -N-G-T-I- at 192 amino acid, -N-T-T-A at 215 amino acid, -N-F-T-E at 373 amino acid and -N-V-T-A- at 408 amino acid were the most possible N-glycosylation sites. Furthermore, the relative transcription level of the PVGOX gene was also stimulated in the presence of 4% (w/v) of calcium carbonate and 0.5 % (v/v) of CSL in the production medium compared with that of the PVGOX gene when the fungal strain F1 was grown in the absence of calcium carbonate and CSL in the production medium, suggesting that under the optimal conditions, the expression of the PVGOX gene responsible for gluconic acid biosynthesis was enhanced, leading to increased gluconic acid production. Therefore, the highly glycosylated oxidase enzyme produced by P. viticola F1 strain might be a good producer in the fermentation process for the industrial level production of gluconic acid.

CRISPR/Cas system: A game changing genome editing technology, to treat human genetic diseases

Genes, are the functional units of heredity that used as an instructors to make proteins either to become the functional or structural part of the cell. Hence, the proteins get more attention because most of the life functions depends on it. Any mutation or alteration in genome sequences results in complete loss of function or formation of abnormal protein which leads to hereditary disorder. Gene therapy on the other hand, used as a remedy, a process that make correction in the gene which is responsible for genomic disorders. The treatment of disease state depends on the understanding of their genetic basis. While, numerous molecular genome editing tools have been developed and are being utilized to translate the abstract of gene therapy into reality, but the problem is still a mystery. The genome editing molecular scissors can be applied to dictate the selected genetic products that can have the therapeutic power. Thus, editing the specific sequences depends on the type of strategies being used by a molecule such is HDR or NHEJ. CRISPR/Cas9 editing technology can use in disease model to study the genitival disorders. One side the CRISPR technology seemed to be extremely accurate but on the other side it has some harmful effects i.e. Cas9 proteins sometimes cuts the similar sequences other than the specific targeted and Off-targeting Sequences etc. Urgent attention and improvement are needed for various implication of CRISPR/Cas9 technology, including the delivery, precision and control over the mention system. This review presents the current scenario of genome editing in vivo and its implications for the future of human genetic disease treatment as well as genome throughput potency.

Sequential extraction procedure for fractionation of Pb and Cr in artificial and contaminated soil

Abstract Metal contamination of soil is due to mining, manufacturing and use of synthetic products (e.g. pesticides, paints, batteries, industrial waste and industrial or domestic sludge) which is a serious environmental problem. Hence, determining chemical forms of metals in soils is important to evaluate their mobility or bioavailability. Both artificial and contaminated soils were sequentially extracted to fractionate metals into the water soluble fraction (WSF), exchangeable fraction (EF), bound to carbonate fraction, bound to metal oxide fraction, organically bound fraction (OBF) and residual fraction (RF). In the case of contaminated soil, Pb and Cr are found to be associated with the carbonate fraction while in artificial soil, Pb bound to WSF and Cr with the Fe/Mn fraction. Chemical properties such as pH, electrical conductivity (EC) and textural classification of concerned soils were also analyzed. Percentage recovery was calculated to check the reliability of processes both in Pb and Cr, and it was found to be more in Cr (66% and 84%) in both artificial and contaminated soil than Pb (5% and 34%) in both soils. Analyses of extracts were carried out by atomic absorption spectrometry (AAS). Results were interpreted in terms of environmental mobility or bioavailability of metals.

Fungal strain Aspergillus flavus F3 as a potential candidate for the removal of lead (II) and chromium (VI) from contaminated soil

Abstract Metal contamination of soil is a serious environmental problem due to mining and use of synthetic products (e.g. pesticides, paints, batteries, and industrial wastes), which are serious threat to human life. The current research is aimed at the remediation of soil contaminated with lead (II) and chromium (VI) using indigenous fungal strains through the comparative study of bioleaching and chemical leaching methods. The removal efficiencies of Pb (II) and Cr (VI) in bioleaching were higher than chemical leaching, where 99% Cr (VI) and 36% Pb (II) were removed by Aspergillus flavus (F3) in bioleaching through the production of approximately 332 mg L-1 malic acid, 213 mg L-1 succinic acid, and 35 mg L-1 citric acid. The removal efficiencies in chemical leaching were 21.30% for Pb (II) and 1.92% for Cr (VI) by malic acid, 29.30% for Pb (II) and 72% for Cr (VI) by succinic acid, 22.21% for Pb (II) and 60.70% for Cr (VI) by citric acid, and 2.20% for Pb (II) and 2.47% for Cr (VI) by oxalic acid. The sequential extraction procedure for Pb (II) and Cr (VI) before and after bioleaching showed that Pb (II) and Cr (VI) mostly bound to stable fractions after bioleaching. Scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX) helped to identify the characteristic changes in the morphology and elemental composition of A. flavus (F3) biomass before and after bioleaching, whereas Fourier transform infrared spectroscopy (FTIR) showed that fungal biomass contain hydroxyl, carboxyl, fatty acids, and amine groups on its surface. The results implied that the fungal strain A. flavus (F3) can be used to remediate soils contaminated with Pb (II) and Cr (VI).