NOPR Collection: Special Issue on Trends in Industrial and Environmental Biotechnology (Guest Editors: Ashok Pandey, Subramanian Babu, K Madhavan Nampoothiri & Claude-Gilles Dussap) [Pages 397-522]

Production and characterization of microbial poly-γ-glutamic acid from renewable resources

Sat, 01 Jul 2017 00:00:00 GMT

Title: Production and characterization of microbial poly-γ-glutamic acid from renewable resources Authors: Anju, Alphonsa Jose; Binod, Parameswaran; Pandey, Ashok Abstract: Poly-γ-glutamic acid (PGA) is an anionic, naturally occurring, biodegradable, edible and water soluble polyamide that has widespread applications viz., thickener, cryoprotectant, drug carrier, biological adhesive, biopolymer flocculant, heavy metal absorber, bitterness relieving agent, etc. Here, we evaluated effectiveness of renewable resources for production of γ-PGA using an isolated Bacillus sp. Lignocellulosic biomass such as rice straw, sugarcane trash, sugarcane bagasse, cotton stalk and sorghum stover were evaluated for production of γ-PGA. Pretreatment was carried out using 1% (w/w) H₂SO₄ for rice straw and 2.5% (w/w) H₂SO₄ for rest of the biomass, followed by enzymatic hydrolysis using cellulase enzyme. Comparative evaluation of sugar yield from various biomass were done and highest percentage of reducing sugar was obtained from rice straw hydrolysate. The hydrolysate was concentrated to obtain 1.01 g/mL of reducing sugar and was added to the production media for the fermentative production of γ-PGA. The maximum PGA obtained was 82.97 g/L by supplementing rice straw hydrolysate (reducing sugar concentration: 4%) by Bacillus amyloliquefaciens. The γ-PGA was characterized by NMR, FTIR, gel permeation chromatography and amino acid analyzer. Present work shows the feasibility of using lignocellulosic biomass as a cheap and economically efficient carbon source for the fermentative production of microbial γ-PGA. Page(s): 405-410

Benzoyloxy-ethyl-carbamic acid: A novel anticancerous secondary metabolite produced by Streptomyces globosus VITLGK011

Sat, 01 Jul 2017 00:00:00 GMT

Title: Benzoyloxy-ethyl-carbamic acid: A novel anticancerous secondary metabolite produced by Streptomyces globosus VITLGK011 Authors: Ravi, Lokesh; Krishnan, Kannabiran Abstract: Marine actinomycetes are known to possess novel anticancer compounds. In this study, we screened marine actinomycetes for isolation and identification of possible cytotoxic anticancer secondary metabolites, if there any. Screening of antagonistic actinomycetes isolates from Rameswaram and Dhanushkodi marine soil samples resulted in the selection of VITLGK011. Molecular taxonomic characterization identified the isolate as Streptomyces globosus VITLGK011. Silica gel column chromatographic separation, purification and characterization by spectroscopic studies lead to the identification of a novel secondary metabolite benzoyloxy-ethyl-carbamic acid (BECA) with a molecular weight 209.2 g/mol and molecular formula C₁₀H₁₁NO₄. BECA demonstrated selective cytotoxicity towards cancer cell lines, in particular against MCF-7. The results of in vivo studies in zebrafish model showed that the compound BECA is non-toxic and capable of reducing tumor progression. In silico studies revealed that BECA by inhibiting PARP1 in MCF-7 cells demonstrated its cytotoxic activity, and hence this molecule can be probed further for its usefulness as a cytotoxic agent. Page(s): 411-420

Conjugation, labeling and characterization of asparaginase bound silver nanoparticles for anticancer applications

Sat, 01 Jul 2017 00:00:00 GMT

Title: Conjugation, labeling and characterization of asparaginase bound silver nanoparticles for anticancer applications Authors: Baskar, G; Lalitha, K; Garrick, BG; Chamundeeswari, M Abstract: Nanomedicine in cancer therapy is an emerging technology over the commercially available drug delivery systems. The loss of drug activity can be prevented by conjugating asparaginase with metal nanoparticles. This necessitates the synthesis of metal nanobiocomposite of L-asparaginase labeled with fluorescein isothiocyanate for better diagnosis and treatment. The present work is focused on the synthesis of silver nanocomposite of fungal L-asparaginase labeled with fluorescein isothiocyanate. The formation of fluorescein isothiocyanate labeled silver nanobiocomposite of asparaginase was confirmed with a broad peak from 360 nm to 500 nm in UV spectrum. The functional group present in the labeled silver nanobiocomposite of asparaginase was analyzed using FTIR spectroscopy while the presence of asparaginase in labeled silver nanobiocomposite was confirmed by ¹H-NMR. The anticancer activity of labeled silver nanobiocomposite of asparaginase as revealed by the fluorescent microscope against MG-63 cancer cell line showed an IC50 value of 62.5 µg/mL. Page(s): 421-426

Optimization of pyroligneous acid production from palm kernel shell and its potential antibacterial and antibiofilm activities

Sat, 01 Jul 2017 00:00:00 GMT

Title: Optimization of pyroligneous acid production from palm kernel shell and its potential antibacterial and antibiofilm activities Authors: Ariffin, Suzami Junaidah; Yahayu, Maizatulakmal; El-Enshasy, Hesham; Malek, Roslinda Abd.; Aziz, Astimar Abd.; Hashim, Najihah Mohd.; Zakaria, Zainul Akmar Abstract: Oil palm plantation generates huge income to Malaysia. At the same time, huge amount of oil palm biomass is also generated which needs to be properly managed. Pyrolysis is one of the approaches available to utilize the oil palm biomass to produce biocharcoal, pyroligneous acid (PA) and bio-oil. PA was produced by condensing the pyrolysis gas emitted and have wide range of potential application including antibacterial activity and antibiofilm activity. In this study, we tried to optimize the operating pyrolysis condition for palm kernel shell to produce maximum yield of PA with highest total phenolic contents (TPC). The optimized PA fraction was evaluated for its antibacterial and antibiofilm properties. Optimum pyrolysis condition resulted in the production of PA containing highest TPC was determined to be at 526°C, heating rate of 10°C/min and nitrogen flow rate of 0.43 L/min. The inhibition zone of concentrated PA extracted by ethyl acetate (CPAE) was determined within 29.3-32.7 mm while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were in the range of 1.95-3.91 and 62.5-125 mg/mL, respectively. CPAE showed the capability to reduce biofilm formation by B. cereus, S. aureus, E. coli and P. aeruginosa up to 80-93% at 64 MIC within 24 h. The biofilm’s metabolite activities were also reduced to 77-93% within 24 h. Results of this study suggest that PA produced from palm kernel shell at optimum condition i.e. containing highest total phenolic contents, has good potential to be used for antibacterial and antibiofilm applications. Page(s): 427-435