Advances and Trends in Biotechnology and Genetics Vol. 2

Xylanases: An Overview

2021-08-02T08:13:08+00:00

Endo-1, 4-β-xylanase (Endo-β-1, 4-xylan, xylanohydrolase; EC. 3.2.1.8, commonly called xylanase) is an industrially important enzyme which degrades xylan randomly and produces xylooligosaccharides, xylobiose and xylose. It is mainly present in microbes and plants but not in animals. Xylanases from fungal and bacterial sources have been extensively studied and produced commercially. Its potential use in paper industries has been discussed which is directly related to reduction in environmental pollution. It has role in bio-bleaching paper pulp and increasing pulp brightness. Besides, it can be exploited for ethanol production and as an additive in animal feedstock to improve its nutritional value. Endo-1, 4-β-xylanase can also be exploited in baking and fruit juice industries. Here, we reviewed its distribution, structural aspects and industrial/ biotechnological applications. Besides, we also discussed studies related to cloning of the gene encoding endo-1, 4-β-xylanase with the objectives of overproducing the enzyme and altering its properties to suit commercial applications.

Hepatorenal Protective Effects of Pomegranate (Punica granatum) Juice against Nicotine Induced Toxicity in Guinea Pigs

2021-08-02T08:18:16+00:00

Background: Pomegranate juice possess a marked antioxidant capacity with a high content in tannins, phenols and flavonoids which can directly or indirectly reduce oxidative damage by preventing the excessive generation of free radicals.

Objectives: The present work aimed to evaluate the effectiveness of pomegranate (Punica granatum) juice as a natural source of antioxidants to minimize the harmful effects of nicotine induced hepatorenal toxicity in Guinea pigs.

Materials and Methods: In this study, twenty four adult male Guinea pigs were used for this study and divided into four groups. The first group was control group, the 2^nd group was administered the pomegranate juice orally, the 3^rdwas the experimental and received intraperitoneal injection of nicotine (6 mg/kg body weight /day), the 4^th one co-administered intraperitoneal injection of nicotine (6 mg/kg body weight /day) and pomegranate juice orally for 8 weeks. Blood samples were obtained for assessment of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ- glutamyltransferase activities, total proteins, albumin, and globulin concentrations, albumin concentration/globulin concentration (A/G) ratio, urea, uric acid, creatinine, sodium ions, and potassium ions concentrations.

Results: In nicotine treated animals, the serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ- glutamyl transferase activities, urea, uric acid, creatinine, and potassium ions concentrations were significantly (p<0.05), increased as compared to the control group. On the other hand, serum total proteins, albumin, globulin, sodium ions concentrations, and A/G ratio of nicotine treated Guinea pigs were significantly (p<0.05) decreased as compared to the control Guinea pigs. Co-administration of pomegranate juice significantly improved all biochemical parameters.

Conclusion: It can be concluded that, nicotine had adverse effects on liver and kidney functions parameters in the blood serum. Pomegranate juice administration showed a remarkable amelioration of these abnormalities in nicotine treated male Guinea pigs. It is recommended that the heavy smokers should be advised to take pomegranate juice as a rich source of antioxidant to prevent the hepatorenal toxicity of nicotine. Further studies are necessary to elucidate exact mechanism of hepatorenal protection and potential usefulness of pomegranate juice as a protective agent against nicotine induced hepatorenal toxicity in clinical trials.

Purification and Characterization of Pectin Methylesterase Produced in Solid State Fermentation by Aspergillus tubingensis

2021-08-02T09:22:38+00:00

Aim: Purification and characterization of pectin methylesterase produced by Aspergillus tubingensis in solid state fermentation.

Study Design: Pectin methylesterase enzyme produced by A. tubingensis was extracted from the fermented solid medium and purified using chromatographic techniques. The purified enzyme was characterized for physico-chemical and kinetic properties.

Place and Duration of Study: Experiments were performed at the School of Biotechnology, Devi Ahilya University, Indore, INDIA and Maharaja Ranjit Singh College of Professional Sciences, Indore, INDIA, between October, 2014 and August, 2015.

Methodology: The enzyme was extracted and purified using ammonium sulphate fractionation, ion exchange chromatography (IEC) using CM- cellulose and gel filtration chromatography (GFC) using Sephadex G-100. The molecular weight of the purified enzyme was determined using native polyacrylamide gel electrophoresis (Native PAGE) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE). The purified enzyme was characterized to determine the pH and temperature optima. Thermostability, pH stability and substrate kinetics were studied for purified pectin methylesterase.

Results: The acidic pectin methylesterase of Aspergillus tubingensis was purified to 20.3 fold with a 47.7% recovery through IEC on CM- cellulose and GFC using Sephadex G-100. The purified enzyme had a specific activity, 112.6 U/mg. The SDS-PAGE revealed that the enzyme was monomeric with a molecular weight of 45.7 kDa. The optimum pH and temperature were 4.6 and 50°C, respectively. This enzyme was stable over a wide pH range (3.0–8.0) and at relatively high temperature at 50°C for 1 h. The Km and Vmax values of pectin methylesterase towards citrus pectin were 33.3 mg/l and 251.2 µmol/ml/min, respectively. In addition, the enzyme activity increased by about 16% in the presence of 5 mM Mg²⁺.

Conclusion: The pectin methylesterase enzyme of A. tubingensis has been purified up to homogeneity and found to be monomeric on SDS-PAGE. Enzyme characterization revealed that purified enzyme worked optimally in acidic conditions and was stable at wider pH range.

Detection of Plasmodium falciparum K13 Propeller A569G Mutation after Artesunate-amodiaquine Treatment Failure in Niger

2021-08-02T09:28:53+00:00

Background: Artemisinin (ART) resistance is a problem that may compromise the elimination of malaria. It is associated with point mutations in the kelch gene PF3D7_1343700 or K13 propeller (pfk13). A recent worldwide map of pfk13 polymorphisms revealed more than 100 non-synonymous (NS) mutations. However, it remains unclear whether these mutations are the result of drug pressure or the expression of a natural polymorphism, because of the scarcity of in-vivo selection of pfK13 mutations data in Africa.

Methodology: This survey evaluates the association between mutations in PfK13 and the response to treatment with artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ) at Gaya, Niger. Mutations in PfK13 before and after treatment were analyzed and used as evidence for the selection of drug resistance following drug pressure.

Results: A total of 161 DNA from patients included in a therapeutic efficacy survey comparing AL vs ASAQ at Gaya sentinel site in 2011 were amplified and sequenced. Five SNPs were identified including 3 non-synonymous (NS) mutations (R528K, A569G and V637I) and 2 synonymous (SY) mutations (C469C and Q613Q). Four SNPs were observed prior to artemisinin-based Combination Therapy (ACT) including 2 NS (R528K and V637I) and 2 SY (C469C and Q613Q) mutations. One NS mutation was selected by ASAQ (PfK13A569G) whereas AL treatment did not select any mutation.

Conclusion: This study suggests that the mutation pfk13A569G is selected by ASAQ. Further mutagenesis studies (CRISPR/Cas9 or Z-Finger Nuclease) will be needed to confirm if pfk13A569G confers resistance to artemisinin.

Optimization of Process Parameters for Improved Lipase Production by Hyperthermophilic Bacillus sonorensis 4R

2021-08-02T09:32:44+00:00

Thermostable lipases isolated from thermophilic bacteria are emerged as industrially and biotechnologically important bio-molecules in recent era of globalization due to their potential to work at high temperatures. Knowledge of growth conditions and nutritional parameters controlling lipase production is necessary to improve its yield and successful development of an industrial bioprocess without increasing the cost of production. We are reporting the individual and interactive effects of process parameters on lipase production by a hyperthermo-alkalophilic strain of Bacillus sonorensis 4R. In the present study, the individual and combined effects of process parameters on lipase production by a hyperthermo-alkalophilic strain of B. sonorensis 4R are studied. Parameters used in this study were incubation period, temperature, initial pH of medium, carbon and nitrogen sources, substrates and metal salts. The isolate showed maximum lipase production after 4 days of incubation at 80°C and pH 8.0 and when growth medium was supplemented with 1% glucose, 1% ammonium sulphate, 100mmol CaSO₄ and by using 1% Tween-80 as lipidic substrate. The combined effects of six variables (pH, temperature, substrate concentration, carbon source, nitrogen source and metal salt) studied in 12 experimental sets showed highest lipase production (51.33 U/mL) by B. sonorensis 4R. In a medium design composed with Tween-80 (1%), CaSO₄ (100 mmol), glucose (0.5%), ammonium sulphate (1%), pH (7.5) and when incubated at 80°C, 6.88 fold enhancement over control was observed in lipase production. In the present study, lipase production from B. sonorensis 4R has been optimized using individual and combined effects of simple and easily manageable process parameters. This knowledge will be helpful to many industrial processes to obtain improved enzyme productivity.

Assessment of Methaemoglobin and Carboxyhaemoglobin Levels among Pregnant Women Infected with Hepatitis B Virus

2021-08-02T09:37:50+00:00

Aims: The goal of this research is to determine plasma levels of MetHb and COHb in pregnant women with hepatitis B, which might enhance oxidative stress and hypoxemic condition of this state if it is not ameliorated on time.

Study Design: Prospective case-control study.

Place and Duration of Study: Antenatal clinic at Primary Health Centres, Sagamu, Ogun State, Nigeria between February, 2015 and August, 2015.

Methodology: Blood levels of MetHb, COHb and bilirubin were determined in ninety four (94) participants (aged 18-40 years), divided into three groups: 33 pregnant women infected with hepatitis B virus, 30 apparently healthy pregnant women and 31 age matched non pregnant women apparently healthy controls. Blood levels of MetHb, COHb and bilirubin were determined using standard spectrophotometric method.

Results: There was progressive increase and decrease in mean blood levels of (TBil and MetHb) and mean blood levels of COHb respectively from controls through pregnant subjects with HBV. PCV and DBil had no specific pattern of differences across the groups.

Conclusion: This study showed a slight increase in blood levels of MetHb in pregnant women with hepatitis B and apparently healthy pregnant women compared to non-pregnant controls, which might enhance oxidative stress and hypoxemic condition of this state. It would also be helpful to incorporate MetHb screening as routine tests for better management of pregnant women especially with HBV.

Kerosene: A Study of Tissue Histology and Serum Vitamin and Heavy Metal Levels of Female Wistar Rats Chronically Exposed

2021-08-02T09:45:07+00:00

Background: Kerosene a commonly available product used for a variety of purposes in many parts of Asia and Africa is sometimes sold in beverage bottles and jerry cans in both commercial and residential places due to inadequate number of filling stations. Therefore excessive exposure through both dermal and oral routes is common.

Objective: This study was embarked upon to ascertain the impact of trace amount of kerosene on tissue histology as well as serum vitamin and heavy metal levels in female Wistar rats.

Methods: Kerosene (0.4 mL/kg body weight) was administered to rats either through the oral or dermal route daily for a period of 30 days. The effects of kerosene administration on tissue histology; serum vitamin levels and serum concentrations of heavy metals were evaluated using hematoxylin- eosin staining technique; high performance liquid chromatography (HPLC); and atomic absorption spectrometry (AAS) respectively. Student’s t test and analysis of variance were used for statistical analysis of data. P <0.05 was considered significant.

Results: Histopathologic presentation such as pulmonary congestion, severely stunted villi, congestion of coronary vessels, and diffuse spongiosis of the cerebral cortex were observed in kerosene administered groups while control group featured no visible lesion. Results of heavy metals revealed that although As, Al and Cd were not significantly different in kerosene exposed groups compared with control, Si was significantly lower (oral), and significantly higer (dermal) compared with control. In addition, using analysis of variance (ANOVA) all estimated vitamins (except pantothenic acid) were significantly different in kerosene exposed groups compared with control.

Conclusion: The results of this study indicate that exposure to this product either through the oral or dermal route may be detrimental to health as it induced adverse alteration in vitamin and heavy metal levels as well as distorted tissue histo-architecture.

Solid State Fermentation Based Olive Pomace Using Streptomyces Strains: A Preliminary Study

2021-08-02T09:50:51+00:00

This study represents a preliminary investigation aimed to assess the possibility to recycle and valorize olive pomace by solid state fermentation (SSF) using Streptomyces strains. The olive pomace was collected from an olive pressing factory (super press system) during the olive fruit pressing season. The study was carried out at IMBE, University Aix Marseille-France, between April 2013 and June 2013 and at LMA, University of Bejaia-Algeria in September 2013. Three Streptomyces strains designated S1M3I, S1M3II and S1M3III were cultured on solid state fermentation based olive pomace at 30°C for 10 days, and subsequently, the lignocellulolytic enzyme activities (xylanase, CMCase and laccase), the viability of the microorganisms and the pH of the resulting substrates, were determined. The fermented substrate pH values remained significantly stable (p ˂ 0.05) throughout the fermentation period for the three strains; they were fluctuated between 6.54 and 6.99. The viability of all Streptomyces strains studied, decreased significantly (p ˂ 0.05) during the first four days of incubation, to reach up 0 cfu/mL of viability and 0 U/g enzymatic activities (xylanase, CMCase and laccase activities) were recorded for the three strains. Streptomyces strains, under the experimental conditions (30°C, pH 7 and 75% of moisture), were unable to grow and produce lignocellulolytic enzymes in solid state fermentation based olive pomace due to the mycelial morphology and Streptomyces developmental cycle, no neglect, the environmental factors. These preliminary results suggest that SSF – Streptomyces system is not suitable for conversion of solid waste from olive processing industry and to produce lignocellulolytic enzymes.

RNA-seq Evaluating Several Custom Microarrays Background Correction and Gene Expression Data Normalization Systems

2021-08-02T10:03:12+00:00

Microarray gene expression technologies represents a widely used tool in transcriptomics and genomics studies worldwide. This technology is stable with the purpose of gene expression differential analysis because of their well-established biostatistics and bioinformatics analysis schemes. However, microarray reliability with regard that analysis typology, depend on probe specificity as well as applied data normalisation and/or background correction procedures. Then, we assessed the performance of 20 different microarrays background correction / gene expression data normalisation combination procedures from “linear models for microarray and RNA-Seq data analysis” package (limma), by comparing significantly differentially expressed genes detected by several custom microarray design strategies, depending on microarray probe size as well as probe set number per transcript model by assuming RNA-Seq approach as benchmark. Basing exclusively on a multivariate statistical clustering surveys, in R programing environment, we showed the pre-eminence of data normalisation (DN) as opposed to noise background correction/subtraction (BS) in microarray expression analysis. Although the combination between (i) gene expression data normalization and (ii) background subtraction procedures (BS+DN), improves the agreement between heterogenic microarray platforms as well as RNA-Seq platform in calling significantly modulated genes, quantile normalisation system combined with all processed background correction procedures has been discriminated as exhibiting highest sensitivity with RNA-Seq (p < 0.05). In conclusion we showed the pre-eminence of microarray data pre-processing step in gene expression differential analysis by according a priority to data normalisation procedure especially to quantile normalisation system contributing in stabilizing gene expression differential analysis results with regard heterogenic custom microarray design strategies (heterogenic microarray platforms).

Diabetes Mellitus: Can Stem Cells be the Answer?

2021-08-02T10:10:13+00:00

This review aims to enlighten the readers regarding the past, present and future of stem cells in the treatment of Diabetes. Diabetes is one of the leading causes of morbidity and mortality, affecting more than 415 million people worldwide. It is estimated that one in ten adults will have diabetes by 2030. Diabetes is mainly due to reduction in β-cell mass which are responsible for insulin production. Exogenous administration of insulin is having good impact on restoring glucose homeostasis, but it does not entirely control the minute-to-minute fluctuations in systemic blood glucose. Recently cellular-based therapies have been established for exogenous insulin administration by modern pump technology. One of the most interesting therapies involves substitution of insulin producing islet cells by transplantation. But lack of donor material and lifelong immunosuppression made the technique unfeasible. These restrictions have led to exploration of other sources of β-cells, one of the prospects being the stem cells. Several types of stem cells have been used to make pancreatic β-cells, including human embryonic stem cells / induced pluripotent stem cells, pancreatic stem / progenitor cells, and non-pancreatic stem cells. There is also evidence of adult β-cells regeneration through β-cell replication and cellular reprogramming. Functional restoration of existing β-cells, transplantation of stem cells or stem cell-derived β-like cells might provide new opportunities for treatment. In conclusion it can be said that the research is still wide open to arrive at the efficient reprogramming of various types of stem cells to destine them towards functional β-cells.

Computational Analysis of Evolutionary Relationship of a Family of Cold Shock Proteins in Ten Mammalian Species

2021-08-02T10:17:42+00:00

Aims: This study was carried out to evaluate the evolutionary relationship of a family of cold shock proteins (CSP) in ten mammalian species using bioinformatics tools and softwares such as Genbank, FASTA, BLAST and MEGA 5.

Sample: Twenty protein sequences of both RBM3 and CIRP proteins of some selected mammalian species were downloaded from NCBI database.

Study Design: Computational analysis to evaluate the evolutionary relationship of the CSP was carried out by estimating the phylogenic relationship of CSP in the different mammalian species studied.

Place and Duration of Study: This study was carried out at the Department of Genetics and Biotechnology, Calabar.

Methodology: The molecular evolution and genetic analysis, version 5 (MEGA 5) software was used to determine the evolutionary relationship of both CIRP and RBM3 in the ten mammalian species studied by constructing phylogenic tree using the amino acid sequences of protein retrieved from NCBI.

Results: The highest identity (100%) was observed between Ovis aries and Bos Taurus; Rattus norvegicus and Mus-musculus while the least percentage identity was observed between Pan troglodytes and Bos taurus (84%). The phylogenic relationship using UPGMA based on Jones-Taylor-Thornton (JTT) matrix model revealed high relationship.

Conclusion: It was observed that evolutionary relationship of CIRP and RBM3 revealed high relatedness among the mammalian species studied.