Current Biotechnology - Volume 11, Issue 1, 2022

Objectives: Fatty acid alkyl esters (FAAEs) are a family of natural neutral lipids and can be produced cleanly and sustainably by esterification of free fatty acids (FFAs) with short chain alcohol using enzymatic catalysts. In this study, the use of lipases was evaluated in enzymatic esterification of oleic acid with ethanol using the combination of biocatalysis and sonochemistry (ultrasound) in the absence of co-solvents. Methods: Reaction parameters, such as type of lipase, amount of enzyme, reaction time, alcohol hydration level and enzyme turnover were evaluated for the enzymatic synthesis of ethyl oleate. Results: C. antarctica lipase provided yields above 95% in less than 10 h with 10% (w/w) of lipase. The use of hydrous ethanol (5% of water) showed a slight drop in yield but remained above 90% of ethyl oleate production. C. antarctica lipase showed no loss efficiency even after 10 reaction cycles. Conclusion: The combination of biocatalysis and ultrasound radiation provided a high yield, showing that the combination of these tools may be a good choice for the enzymatic synthesis of ethyl oleate.

The α-amylase is one of the most promising commercial enzymes with tremendous applications in various industries. Microbial α-amylase shares almost 25-30% of the enzyme market due to its catalytic function in several industries, including sugar, detergent, paper, textile, pharmaceutical industries, etc. The α-amylase hydrolyzes glycosidic linkages of structural components of starch, resulting in maltose, glucose, and high fructose syrups. Starch, the second most abundant organic substance on the Earth, is a readily available, low-cost renewable substrate mainly used in biorefinery and food industries. Amylases are ubiquitous in nature due to their involvement in carbohydrate metabolism. The α-amylases of microbial origin have technical advantages as compared to animal and plant origin. Considering physicochemical properties, bacterial α-amylases are most diverse. However, for industrial purposes, these properties of the biocatalyst, either individually or in a combination, are required to modify through genetic and protein engineering according to the targeted process. The review presents an overview of the current findings of microbial sourced α- amylases, commercial applications, market trends in relevant industries, and achieved improvements in thermostability, catalytic function, pH tolerance, substrate, and product specificities through recombinant DNA technology and protein engineering.

Lupus is a heterogeneous and inflammatory autoimmune disease that affects the immune system of the body. This disease affects multiple tissues and organs. The most frequent kind of lupus is systemic lupus erythematosus (SLE). SLE is an autoimmune illness in which the immune system targets the body's tissues, resulting in extensive inflammation and tissue destruction in the organs involved. Joints, skin, brain, lungs, kidneys, and blood vessels can all be affected. It appears to be a form of B-cell disease in which autoantibodies attack the cells. Systemic lupus erythematosus autoimmune diseases involve different treatment methods. These abnormalities are due to the presence of autoantibodies, and these contribute to the degeneration of the body’s immune system. In this review, we will focus on various therapies, including SLE treatments, such as B-cell therapy, cytokine therapy, interferon targets, and anticomplementary therapies, all of which have become challenging. We will also discuss post-marketing use and ongoing clinical trials, as well as safety and effective doses.

Background: Salmonella serovars contamination of food items shows a negative effect on the food industry and causes a great hazard for the consumers. Although developed hygiene methods, Salmonella serovars are still a high risk to human health, and new methods for the identification of Salmonella spp. are needed. Objective: Bacteriophages have been considered a good method for detecting bacteria owing to their high target cell specificity, simplicity and cheapness. Bacteriophages can be used for biocontrol of Salmonella spp. without the cultural methods. Moreover, phages or phage-derived proteins can also be used to detect quickly and specifically bacteria in food. Methods: This study provides bacteriophage expression in six multidrug-resistant Salmonella isolated from retail meats in Hanoi, Vietnam using mRNA sequencing. Results: Our results showed that diverse bacteriophages are naturally present in retail meats (chicken, beef, and pork meat), and phage Salmon_118970_sal3_NC_031940 is the most common phage in Salmonella on the retail meats. Conclusion: These results provide useful information for developing a new method to detect Salmonella serovars effectively. Further surveillance programs and research are a necessity to limit the spread of multidrug-resistant Salmonella spp.

Background: Polyhydroxyalkanoates (PHAs) are biodegradable, biocompatible, and non-toxic polymers synthesized by bacteria that may be used to displace some petroleum-based plastic materials. One of the major barriers to the commercialization of PHA biosynthesis is the high cost of production. Objective: Oxygen-limitation is known to greatly influence bacterial cell growth and PHA production. In this study, the growth and synthesis of medium chain length PHAs (mcl-PHAs) by Pseudomonas putida LS46, cultured in batch-mode with octanoic acid, under oxygen-limited conditions, was modeled. Methods: Four models, including the Monod model, incorporated Leudeking-Piret (MLP), the Moser model incorporated Leudeking-Piret (Moser-LP), the Logistic model incorporated Leudeking- Piret (LLP), and the Modified Logistic model incorporated Leudeking-Piret (MLLP) were investigated. Kinetic parameters of each model were calibrated using the multi-objective optimization algorithm, Pareto Archived Dynamically Dimensioned Search (PA-DDS), by minimizing the sum of absolute error (SAE) for PHA production and growth simultaneously. Results and Conclusion: Among the four models, MLP and Moser-LP models adequately represented the experimental data for oxygen-limited conditions. However, the MLP and Moser-LP models could not adequately simulate PHA production under oxygen-excess conditions. Modeling cell growth and PHA will assist in the development of a strategy for industrial-scale production.

Background: Diabetes mellitus is a disease and endocrine disorder. It is a growing health problem in various countries. The prevalence of diabetes is rising worldwide; around 5.4% rise in patients with diabetes is expected by 2025. The World Health Organization (WHO) has reported that 173 million adults are suffering from diabetes mellitus in developing counties. In this research, estimation of glucose levels was performed in Wistar rats post-induction of diabetes by streptozotocin. Metformin has been used as a standard dose for treatment. This study demonstrated the acute oral toxicity and subacute oral toxicity of ethanolic extract of Saraca asoca leaves and Asparagus racemosus roots and evaluated the antidiabetic activity. Objective: This study aimed to evaluate the acute toxicity and sub-acute toxicity of the polyherbal ethanolic extract on vital organs. The visible changes in the organs of each group of Wistar rats were also determined in this study. Moreover, the hypoglycaemic action of the polyherbal extract of Saraca asoca and Asparagus racemosus was also explored. Methods: Wistar rats were divided into four groups for assessing acute oral toxicity. Groups were administered doses of 5,50, 300, and 2000mg/kg body weight of the polyherbal extract. Subacute oral toxicity studies were performed by administering a polyherbal extract of 250, 500, 1000mg/kg body weight. For evaluating the antidiabetic activity, animals were divided into 5 groups. In group 1 (normal control), saline was administered; in group 2, standard drug Metformin was administered; in group 3, no drug was given to rats with diabetes (Streptozotocin-Induced diabetic with 150mg/kg body weight), thus forming the diseased group. In group 4, ethanolic extract with 100mg/kg group was administered, and in group 5, ethanolic extract of 200mg/kg was administered. On the last day, the blood glucose levels and body weights of rats were examined. Histopathology studies were conducted by sacrificing the animals, isolating the organs, such as tissue pancreas, spleen, heart, lungs, liver, and kidney, and placing them on slides using a microscopic examination. Data were selected by searching the articles in the databases, such as NCBI, Web of Science and ScienceDirect, and PubMed from 1989 to 2020 by using keywords, such as “Antidiabetic,” “Saraca indica,” “Asparagus racemosus,” “ethanolic polyherbal extract,” “oral toxicity study,” “histopathology,” and “Streptozotocin.” Results: The polyherbal ethanolic extract of Saraca asoca and Asparagus racemosus at a dose of 100 mg/kg and 200 mg/kg showed better effects against streptozotocin-induced diabetic rats having 150 mg/kg body weight. Regarding acute toxicity and subacute oral toxicity studies, all the extracts showed significant values (P <0.05) and were found to be safe and non-toxic. The body weight was also improved; no inflammation and erosion were seen on any organs of the Wistar rat in a histopathology analysis. Conclusion: The polyherbal ethanolic extract of Saraca asoca and Asparagus racemosus showed hypoglycaemic activity against STZ-induced diabetes in experimental Wistar rats. The results showed the beneficial effects of these ethanolic extracts, improving the body weight and changes in lipid metabolism and protecting the organs of Wistar rats, such as the liver, kidney, spleen, pancreas, lungs, and heart, against impairment of blood glucose. All organs were weighted, tissues from organs were isolated, then stained using eosin dye, and changes were observed by microscopy photos. No signs of inflammation and erosion were reported at the end of the study, indicating the healing action of the extract.

Background: The most widely used thermostable enzymes are the amylases in the starch industry. These are among the most important enzymes and are of great significance in present day biotechnology. Objective: The main objective of the present study was to enhance α-amylase production from Bacillus licheniformis using Response Surface Methodology (RSM) and the purification of the enzyme to homogeneity. Methods: Bacterial culture producing α-amylase isolated from hot spring (Himachal Pradesh) was identified as Bacillus licheniformis using 16S rDNA gene sequencing (NCBI Accession No.: KR340466). Medium components and physical culture parameters viz. pH, temperature, inoculum size, peptone concentration and starch concentration were optimized using RSM. Among these five factors, three factors (starch concentration, peptone concentration and inoculum size) had a positive effect on amylase production. A 4.09-fold increase in the production of α-amylase from B. licheniformis was achieved using RSM as compared to One Factor At a Time. The enzyme was purified by using Diethylaminoethyl Cellulose column chromatography and subsequently by Sephadex G-75 gel filtration chromatography. Results: A purification fold of 23.39 and a yield of 12.12% were observed. A single band of 33 kDa was obtained using Sodium Dodecyl Sulphate (SDS) and native-Poly Acrylamide Gel Electrophoresis (PAGE), which indicated that the enzyme was purified to homogeneity and was a monomer. The enzyme showed stability at 50 and 65°C temperatures and at alkaline pH. Conclusion: The stability of purified enzyme at high temperatures and alkaline pH suggested its wide application in textile, detergent and paper industries.

Background: Retinoblastoma, a malignancy occurring in the juvenile cells of the retina, is responsible for light detection. It is one of the most emerging ra re childhood and infant cancer. It is initiated by the mutation in Rb1, a first tumor suppressor gene located on chromosome 13q14. Rb1 protein is responsible for cell cycle regulation. Methods: In our study, secondary and 3D-Structural predictions of Rb1^WT and Rb1^R661W were made by comparative or homology modeling to find any structural change leading to the disruption in its further interactions. Quality assurance of the structures was done by Ramachandran Plot for a stable structure. Both the proteins were then applied by docking process with proteins of interest. Results: Secondary structure showed a number of mutations in helixes, β-Hairpins of Rb1^R661W. The major change was the loss of β-Hairpin loop, extension and shortening of helixes. 3D comparison structure showed a change in the groove of Rb1^R661W. Docking results, unlike RB1 ^WT, had different and no interactions with some of the proteins of interest. This mutation in Rb1 protein had a deleterious effect on the protein functionality. Conclusion: This study will help to design the appropriate therapy and also understand the mechanism of disease of retinoblastoma, for researchers and pharmaceuticals.

Background: Essential oils (EOs) are a mixture of volatile compounds of plant origin, which possess substantial biological activities such as antioxidant, antimicrobial, and antifungal activity. Objective: This study aimed to determine the chemical composition, antioxidant, and antibacterial activity of essential oil isolated from Cymbopogon winterianus Jowitt. Methods: The hydro-distillation method was used for the isolation of essential oil. The chemical composition of the isolated essential oil was analyzed using the gas chromatography/mass spectrometry (GC-MS) technique. Antioxidant activity was determined using a 2,2-diphenyl-1- picrylhydrazyl (DPPH) free radical scavenging assay, and the IC50 value was calculated. The welldiffusion method was applied for the antibacterial activity, and the zone of inhibition (ZOI) was measured. Results: The essential oil from Cymbopogon winterianus Jowitt was isolated with a 0.5% yield. Gas Chromatography-Mass Spectrometry(GC-MS) analysis reported 19 different compounds, out of which, Geraniol (28.87%), Citronellal (11.85%), Citronellol (10.88%), Geranial (9.19%), trans- Geranyl acetate (9.11%), and Neral (8.02%) were found to be the major constituents. The essential oil was a promising antioxidant with an IC50 value of 0.458±0.39μg/mL compared to the standard Quercetin of 1.187±0.22μg/mL. In addition, the isolated essential oil revealed antibacterial activity against Staphylococcus aureus (ZOI=13.2mm), Bacillus subtilis (ZOI=9.9mm), and Enterococcus faecalis (ZOI=8.4mm). Conclusion: The essential oil isolated from Cymbopogon winterianus Jowitt exhibits antioxidant and antibacterial activity, implying that it could find use in modern medicine.