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.

Hepatitis E is a liver disease caused by the pathogen hepatitis E virus (HEV). The largest polyprotein open reading frame 1 (ORF1) contains a nonstructural Y-domain region (YDR) whose activity in HEV adaptation remains uncharted. The specific role of disordered regions in several nonstructural proteins has been demonstrated to participate in the multiplication and multiple regulatory functions of the viruses. Thus, intrinsic disorder of YDR including its structural and functional annotation was comprehensively studied by exploiting computational methodologies to delineate its role in viral adaptation. Based on our findings, it was evident that YDR contains significantly higher levels of ordered regions with less prevalence of disordered residues. Sequence-based analysis of YDR revealed it as a “dual personality” (DP) protein due to the presence of both structured and unstructured (intrinsically disordered) regions. The evolution of YDR was shaped by pressures that lead towards predominance of both disordered and regularly folded amino acids (Ala, Arg, Gly, Ile, Leu, Phe, Pro, Ser, Tyr, Val). Additionally, the predominance of characteristic DP residues (Thr, Arg, Gly, and Pro) further showed the order as well as disorder characteristic possessed by YDR. The intrinsic disorder propensity analysis of YDR revealed it as a moderately disordered protein. All the YDR sequences consisted of molecular recognition features (MoRFs), i.e., intrinsic disorder-based protein–protein interaction (PPI) sites, in addition to several nucleotide-binding sites. Thus, the presence of molecular recognition (PPI, RNA binding, and DNA binding) signifies the YDR’s interaction with specific partners, host membranes leading to further viral infection. The presence of various disordered-based phosphorylation sites further signifies the role of YDR in various biological processes. Furthermore, functional annotation of YDR revealed it as a multifunctional-associated protein, due to its susceptibility in binding to a wide range of ligands and involvement in various catalytic activities. As DP are targets for regulation, thus, YDR contributes to cellular signaling processes through PPIs. As YDR is incompletely understood, therefore, our data on disorder-based function could help in better understanding its associated functions. Collectively, our novel data from this comprehensive investigation is the first attempt to delineate YDR role in the regulation and pathogenesis of HEV.

Chemical control has been the most efficient method in mosquito control, the development of insecticide resistance in target populations has a significant impact on vector control. The use of agricultural pesticides may have a profound impact on the development of resistance in the field populations of malaria vectors. Our study focused on insecticide resistance and knockdown resistance (kdr) of Anopheles arabiensis populations from Northern Sudan, related to agricultural pesticide usage. Anopheles arabiensis from urban and rural localities (Merowe and Al-hamadab) were fully susceptible to bendiocarb 0.1% and permethrin 0.75% insecticides while resistant to DDT 4% and malathion 5%. The population of laboratory reference colony F189 from Dongola showed a mortality of 91% to DDT (4%) and fully susceptible to others. GLM analysis indicated that insecticides, sites, site type, and their interaction were determinant factors on mortality rates (P < 0.01). Except for malathion, mortality rates of all insecticides were not significant (P > 0.05) according to sites. Mortality rates of malathion and DDT were varied significantly (P < 0.0001 and P < 0.05 respectively) by site types, while mortality rates of bendiocarb and permethrin were not significant (P >0.05). The West African kdr mutation (L1014F) was found in urban and rural sites. Even though, the low-moderate frequency of kdr (L1014F) mutation was observed. The findings presented here for An. arabiensis showed no correlation between the resistant phenotype as ascertained by bioassay and the presence of the kdr mutation, with all individuals tested except the Merowe site which showed a moderate association with DDT (OR= 6 in allelic test), suggesting that kdr genotype would be a poor indicator of phenotypic resistance. The results provide critical pieces of information regarding the insecticide susceptibility status of An. arabiensis in northern Sudan. The usage of the same pesticides in agricultural areas seemed to affect the Anopheles susceptibility when they are exposed to those insecticides in the field. The kdr mutation might have a less role than normally expected in pyrethroids resistance; however, other resistance genes should be in focus. These pieces of information will help to improve the surveillance system and The implication of different vector control programs employing any of these insecticides either in the treatment of bed nets or for indoor residual spraying would achieve satisfactory success rates.

The coexistence of cirrhosis complicates the early detection of hepatocellular carcinoma (HCC). Thus, novel biomarkers for HCC early detection are needed urgently. Traditionally, HCC detection is carried out by evaluating alpha-fetoprotein (AFP) levels combined with imaging techniques. This work aimed to assess interleukin (IL-6) and insulin-like growth factor 2 (IGF 2) as possible HCC markers in comparison to AFP in patients with and without HCC. ROC analysis showed that IGF2 had the highest area under the curve (AUC) for discriminating HCC from liver cirrhosis (0.86), followed by IL6 (0.82), AFP (0.72), and platelet count (0.6). A four-marker model was developed and discriminated HCC from liver cirrhosis with an AUC of 0.97. The best cut-off was 1.28, at which sensitivity and specificity were 90% and 85%, respectively. For small tumor (< 2 cm), the model had an AUC of 0.95 compared to AFP (0.72). Also, the model achieved perfect performance with AUC of 0.93, 0.94, and 0.95 for BCLC (0-A), CLIP (0-1), and Okuda (stage I), respectively, compared to AFP (AUC of 0.71, 0.69, and 0.67, respectively). The four markers may serve as a diagnostic model for HCC early stages and help overcome AFP poor sensitivity.

Penicillin G amidase/acylases from microbial sources is a unique enzyme that belongs to the N-terminal nucleophilic hydrolase structural superfamily. It catalyzes the selective hydrolysis of side chain amide/acyl bond of penicillins and cephalosporins whereas the labile amide/acyl bond in the β-lactam ring remains intact. This review summarizes the production aspects of PGA from various microbial sources at optimized conditions. The minimal yield from wild strains has been extensively improved using varying strain improvement techniques like recombination and mutagenesis; further applied for the subsequent synthesis of 6-aminopenicillanic acid, which is an intermediate molecule for synthesis of a wide range of novel β-lactam antibiotics. Immobilization of PGA has also been attempted to enhance the durability of enzyme for the industrial purposes. The present review provides an emphasis on exploitation of E. coli to enhance the microbial production of PGA. The latest achievements in the production of recombinant enzymes have also been discussed. Besides E. coli, other potent microbial strains with PGA activity must be explored to enhance the yields.

Sự kích thích hemoglobin thai nhi (HbF) đã cho thấy tiềm năng trong việc điều trị các bệnh β-hemoglobinopathies. Kích thích HbF trong β-thalassemia có thể vượt qua sự tạo huyết không hiệu quả và do đó chấm dứt phụ thuộc vào truyền máu đối với những bệnh nhân trước đây cần truyền máu. Một số miRNA đã được tìm thấy có khả năng tái kích hoạt biểu hiện γ-globin và tăng HbF. Trong nghiên cứu này, chúng tôi nhằm mục đích điều tra sự biểu hiện của 4 miRNA (miR-15a, miR-16-1, miR-96, và miR-486-3p) ở những bệnh nhân thalassemia có HbF cao và tương quan mức độ của chúng với mức HbF của bệnh nhân, sau đó, để dự đoán vai trò chính xác của các miRNA đã nghiên cứu trong tạo huyết, một phân tích sinh tin học đã được thực hiện. Chúng tôi đã thực hiện phân tích sinh tin học này để xác định mạng lưới các gen được miRNA điều chỉnh và điều tra thêm sự tương tác giữa tất cả chúng thông qua sự tham gia của chúng trong quá trình tạo huyết. Trong nghiên cứu này, sự biểu hiện khác biệt đã được đo bằng qRT-PCR cho 40 bệnh nhân có HbF cao và so sánh với 20 đối chứng khỏe mạnh. Phân tích sinh tin học đã được tiến hành bao gồm chú thích chức năng và phân tích làm giàu đường đi. Các microRNA đã nghiên cứu được điều chỉnh đáng kể ở bệnh nhân thalassemia có tương quan với HbF. Chú thích chức năng và phân tích làm giàu đường đi đã tiết lộ vai trò chính của miR-486-3p và miR-15a trong kích thích HbF. MiR-486-3p và miR-15a là then chốt cho việc kích thích HbF. Cần có thêm các nghiên cứu xác thực.

Argentina’s geothermal areas are niches of a rich microbial diversity. In 2020, species of Bacillus cytotoxicus were isolated for the first time from these types of pristine natural areas. Bacillus cytotoxicus strains demonstrated the capability to grow and degrade chicken feathers with the concomitant production of proteases with keratinolytic activity, enzymes that have multitude of industrial applications. The aim of this research was to study the production of the proteolytic enzymes and its characterization. Also, feather protein hydrolysates produced during fermentation were characterized. Among the thermotolerant strains isolated from the Domuyo geothermal area (Neuquén province, Argentina), Bacillus cytotoxicus LT-1 and Oll-15 were selected and put through submerged cultures using feather wastes as sole carbon, nitrogen, and energy source in order to obtain proteolytic enzymes and protein hydrolysates. Complete degradation of feathers was achieved after 48 h. Zymograms demonstrated the presence of several proteolytic enzymes with an estimated molecular weight between 50 and > 120 kDa. Optimum pH and temperatures of Bacillus cytotoxicus LT-1 crude extract were 7.0 and 40 °C, meanwhile for Oll-15 were 7.0 and 50 °C. Crude extracts were inhibited by EDTA and 1,10 phenanthroline indicating the presence of metalloproteases. Feather protein hydrolysates showed an interesting antioxidant potential measured through radical-scavenging and Fe3+-reducing activities. This work represents an initial approach on the study of the biotechnological potential of proteases produced by Bacillus cytotoxicus. The results demonstrated the importance of continuous search for new biocatalysts with new characteristics and enzymes to be able to cope with the demands in the market.