Journal of Genetic Engineering and Biotechnology

Exopolysaccharides (EPSs) từ vi sinh vật là các biopolymer tự nhiên vô hại quan trọng, được sử dụng trong các ứng dụng bao gồm dược phẩm, nutraceuticals và thực phẩm chức năng, mỹ phẩm và thuốc trừ sâu. Nhiều loại vi sinh vật có khả năng tổng hợp và bài tiết EPSs với các tính chất hóa học và cấu trúc khiến chúng phù hợp với một số ứng dụng quan trọng. Vi sinh vật bài tiết EPS ra bên ngoài màng tế bào của chúng, dưới dạng chất nhờn hoặc “thạch” vào môi trường ngoại bào. Những vi sinh vật sản xuất EPS này rất phổ biến và có thể được phân lập từ các môi trường nước và đất, chẳng hạn như nước ngọt, nước biển, nước thải và đất. Chúng cũng đã được phân lập từ những môi trường cực đoan như suối nước nóng, nước lạnh, các môi trường ưa muối và đầm lầy muối. Gần đây, EPS vi sinh vật đã thu hút sự quan tâm cho các ứng dụng như tác nhân kết tụ sinh học môi trường nhờ tính chất phân hủy được và không độc hại của chúng. Tuy nhiên, cần có thêm nỗ lực để sản xuất EPS vi sinh vật một cách hiệu quả về chi phí và quy mô công nghiệp. Bài đánh giá này tập trung vào các exopolysaccharides thu được từ nhiều vi sinh vật ưa cực, quá trình tổng hợp của chúng và tối ưu hóa sản xuất để cải thiện chi phí và năng suất. Chúng tôi cũng đã khám phá vai trò và ứng dụng của chúng trong các tương tác giữa nhiều sinh vật khác nhau.

Natural dyes are present in living organisms such as animals and plants and microorganisms such as fungi, bacteria, algae, and yeast. Pigments are fast and easy growth by using cheap components and do not effect by environmental conditions because they required some physical factors like heat, light, and pH and also they have many biotechnological applications such as medical and industrial needs. The natural pigments can act as antimicrobial agents and are used in drug manufacturing. Also, it can be used in the food industry as natural colorants instead of the synthetic colorants due to their safety on human health and low toxicity when emitted into the environment. A pigmented actinomycetes LS1 strain isolated from El Mahmoudia canal (sediment soil) located in Egypt was microscopically examined and identified as Streptomyces sp. by molecular approach. Extraction, purification, and characterization of produced red pigment metabolite like carotenoids related were established based on spectroscopic studies and comparing the data from the literature. Factors (nutritional and physical) influencing red pigmentation by this isolate were investigated through One Variable At Time (OVAT), and then, the optimal levels of the significant key variables were recorded. Also, the productivity yield reached 30 mg of dried purified pigment/gram dry weight. The biological activity of the red product was tested against Gram-positive and Gram-negative marine bacterial pathogens; the recorded antimicrobial activity is more prominent against (P. aeruginosa ATCC 9027, K. pneumoniae ATCC 13883, S. aureus ATCC 6538, B. subtilis ATCC 6633 and E. coli ATCC 10418) at nearly 0.07 mg mL−1 concentration. Also, the tested red pigment showed a positive antifouling activity (AF) against marine microbes; the activity increased by increasing the pigment concentrations from 1 to 3 mg mL−1. The present work focused on the optimization of culture conditions for the production of red pigment by Streptomyces sp. LS1; then, the antibacterial activity and antifouling activity of the produced pigments were tested.

The point of the present investigation was to blend effective chitosan nanoparticles (CNPs) loaded with Pterocarpus marsupium (PM) heartwood extract and evaluate its biomedical applications. Various plant extract concentrations (PM-CNPs-1, PM-CNPs-2, PM-CNPs-3) are used to synthesize chitosan nanoparticles and optimized to acquire a stable nanoparticle formulation. The entrapment efficiency and in vitro release studies of the plant extract encapsulated in CNPs are estimated. The PM-loaded CNPs were characterized by X-ray diffraction, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The synthesized chitosan nanoparticles were evaluated for their alpha-amylase inhibitory activity and inhibition of albumin denaturation activity. The XRD pattern of PM-CNPs shows less number of peaks at low intensity due to the interaction of chitosan with sodium tripolyphosphate. The FT-IR spectrum with peaks at 1639.55 and 1149.02 cm−1 confirms the formation of chitosan nanoparticles. The size of the nanoparticles ranges between 100 and 110 nm with spherical shape illustrated by SEM and TEM analysis. The nanoparticle formulation with 10% plant extract concentration (PM-CNPs-2) showed optimum particle size, higher stability, enhanced entrapment efficiency, and sustained drug release characteristics. Synthesized chitosan nanoparticles have shown a significant increase in alpha-amylase inhibition and appreciable anti-inflammatory activity as measured by inhibition of protein denaturation. The investigation reports the eco-friendly, cost-effective method for synthesizing chitosan nanoparticles loaded with Pterocarpus marsupium Rox.b heartwood extract.

Mycobacterium colombiense is an acid-fast, non-motile, rod-shaped mycobacterium confirmed to cause respiratory disease and disseminated infection in immune-compromised patients, and lymphadenopathy in immune-competent children. It has virulence mechanisms that allow them to adapt, survive, replicate, and produce diseases in the host. To tackle the diseases caused by M. colombiense, understanding of the regulation mechanisms of its genes is important. This paper, therefore, analyzes transcription start sites, promoter regions, motifs, transcription factors, and CpG islands in TetR family transcriptional regulatory (TFTR) genes of M. colombiense CECT 3035 using neural network promoter prediction, MEME, TOMTOM algorithms, and evolutionary analysis with the help of MEGA-X. The analysis of 22 protein coding TFTR genes of M. colombiense CECT 3035 showed that 86.36% and 13.64% of the gene sequences had one and two TSSs, respectively. Using MEME, we identified five motifs (MTF1, MTF2, MTF3, MTF4, and MTF5) and MTF1 was revealed as the common promoter motif for 100% TFTR genes of M. colombiense CECT 3035 which may serve as binding site for transcription factors that shared a minimum homology of 95.45%. MTF1 was compared to the registered prokaryotic motifs and found to match with 15 of them. MTF1 serves as the binding site mainly for AraC, LexA, and Bacterial histone-like protein families. Other protein families such as MATP, RR, σ-70 factor, TetR, LytTR, LuxR, and NAP also appear to be the binding candidates for MTF1. These families are known to have functions in virulence mechanisms, metabolism, quorum sensing, cell division, and antibiotic resistance. Furthermore, it was found that TFTR genes of M. colombiense CECT 3035 have many CpG islands with several fragments in their CpG islands. Molecular evolutionary genetic analysis showed close relationship among the genes. We believe these findings will provide a better understanding of the regulation of TFTR genes in M. colombiense CECT 3035 involved in vital processes such as cell division, pathogenesis, and drug resistance and are likely to provide insights for drug development important to tackle the diseases caused by this mycobacterium. We believe this is the first report of in silico analyses of the transcriptional regulation of M. colombiense TFTR genes.

In fungi, like other eukaryotes, protein turnover is an important cellular process for the controlling of various cellular functions. The ubiquitin-proteasome pathway degrades some selected intracellular proteins and F-box proteins are one of the important components controlling protein degradation. F-box proteins are well studied in different model plants however, their functions in the fungi are not clear yet. This study aimed to identify the genes involved in protein degradation for disease development in the Macrophomina phaseolina fungus. In this research, in silico studies were done to understand the distribution of F-box proteins in pathogenic fungi including Macrophomina phaseolina fungus. Genome-wide analysis indicates that M. phaseolina fungus contained thirty-one F-box proteins throughout its chromosomes. In addition, there are 17, 37, 16, and 21 F-box proteins have been identified from Puccinia graminis, Colletotrichum graminicola, Ustilago maydis, and Phytophthora infestans, respectively. Analyses revealed that selective fungal genomes contain several additional functional domains along with F-box domain. Sequence alignment showed the substitution of amino acid in several F-box proteins; however, gene duplication was not found among these proteins. Phylogenetic analysis revealed that F-box proteins having similar functional domain was highly diverse form each other showing the possibility of various function. Analysis also found that MPH_00568 and MPH_05531 were closely related to rice blast fungus F-box protein MGG_00768 and MGG_13065, respectively, may play an important role for blast disease development. This genome-wide analysis of F-box proteins will be useful for characterization of candidate F-box proteins to understand the molecular mechanisms leading to disease development of M. phaseolina in the host plants.

Artocarpus heterophyllus is an important tropical agroforestry species that bears multiple applications. However, the population of this species is reduced due to various anthropogenic activities. For this reason, in vitro approach is needed to propagate or conserve this species as in vivo propagation methods face various obstacles. In this respect, the present investigation was undertaken to produce genetically stable jackfruit trees through in vitro technology. In vivo grew shoot tips were harvested on Murashige and Skoog (MS) medium containing several plant growth regulators to achieve this. The 6-benzylaminopurine (BAP) at the concentration of 1.5 mg L-1, indole-3-butyric acid (IBA) at 0.5 mg L-1, and α-naphthaleneacetic acid (NAA) at 0.1 mg L-1 in combination on MS media yielded superior shoot response (94.44%), longest shoot length (4.02 cm), and the maximum number of shoots per explant (4.78). They were further multiplied by repeated subculturing on the same media composition and the third subculture resulted in a maximum number of shoots (5.92) with the largest shoot length (5.85 cm). Among the different media screened for rooting, the ¼ MS media yielded 94.44% rooting response, the longest root length (3.78 cm), and the maximum number of roots per shoot (8.44) with 0.1 mg L-1 NAA, 0.5 mg L-1 IBA and 0.1 mg L-1 BAP in combination. Primary hardening showed 88.89% of plant survival under greenhouse conditions after 4 weeks of incubation having a sterilized mixture of garden soil and vermiculite mixture (1:1, w/w). It increased to 90.60% after the secondary hardening process in a vermiculite-soil mixture (2:1; w/w). No polymorphism was detected on random amplification of polymorphic DNA (RAPD) profiling between the mother plant and hardened plants, indicating high genetic stability among the clones. This is the first report of the genetic fidelity study of in vitro grown regenerants of A. heterophyllus. This study established a micropropagation protocol for genetically uniform in vitro regeneration of this species to supply plant resources to various industries or conservation of elite germplasm.