Electronic Journal of Biotechnology最新文献

Background

Xylitol, a five-carbon polyalcohol, is used in the food and pharmaceutical industries and as a building block in the synthesis of high-value chemicals. It can be sustainably produced from renewable sources through xylose assimilating microbe fermentation.

Results

We screened microbial strains for xylitol production and identified Wickerhamomyces anomalus Z1 as a key xylitol producer. Utilizing lignocellulosic biomass hydrolysates for xylitol production poses challenges due to microbial sensitivity to inhibitors from biomass pre-treatment. In this study, an adaptive laboratory evolution (ALE) of W. anomalus Z1 was performed by culturing the yeast in a mineral medium supplemented with gradual increases of sugarcane bagasse hemicellulosic hydrolysate (SCHH) obtained by intensified steam explosion pretreatment. The performance of the adapted yeast, named Wickerhamomyces anomalus ALE, was assessed in comparison to the wild-type strain regarding its capacity to produce xylitol using SCHH. The evolved yeast reached a xylitol yield of 0.11 g xylitol/g xylose whereas the wild-type strain could not produce xylitol. Removing acetic acid from SCHH enhanced W. anomalus ALE performance, with optimal results at 75% hydrolyzed hemicellulose, yielding 0.44 g xylitol/g xylose and 13.41 g/L xylitol.

Conclusions

This study demonstrates the potential of W. anomalus ALE in successfully valorizing the hemicellulosic fraction of sugarcane bagasse for sustainable xylitol production.

How to cite: Bonfiglio F, Cagno M, Nuñez L, et al. Xylitol production by a Wickerhamomyces anomalus strain adapted for enhanced tolerance to sugarcane bagasse hemicellulosic hydrolysate with high content of fermentation inhibitors. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.05.004.

Background

L-asparaginase (L-ASNase) is an essential enzyme used to treat acute lymphoblastic leukemia (ALL) by depleting L-asparagine, a vital nutrient for leukemia cells. However, its clinical use is challenged by adverse effects linked to its bacterial origin and L-glutaminase (L-GLNase) co-activity. This study aims to identify fungi capable of producing L-ASNase with reduced L-GLNase co-activity.

Results

Among the fungal iolates, isolate JK12 and ChL11 showed high L-ASNase activity (34.04 ± 1.83^a U/ml and 30.84 ± 0.53^b U/ml, respectively) with reduced L-GLNase co-activity (4.95 ± 0.28^c U/ml and 4.80 ± 0.02^d U/ml, respectively). Sequencing of the internal transcribed spacer (ITS) region of these isolates identified them as Candida palmioleophila isolate JK12 (≥99% identity with Candida genus) and Trichosporon asahii isolate ChL11 (≥98% identity with Trichosporon genus). Moreover, these isolates exhibited distinct preferences for carbon (C) and nitrogen (N) sources, as well as culture conditions for L-ASNase production. C. palmioleophila isolate JK12 demonstrated the highest L-ASNase production in fructose and yeast extract (67.6 ± 0.04^a U/ml and 51.4 ± 0.04^a U/ml, respectively), following 96 h of incubation at 25°C (43.8 ± 1.22^a U/ml, 55.8 ± 0.02^a U/ml, respectively), with an agitation speed of 100 rpm (59.9 ± 0.04^a U/ml). On the other hand, T. asahii isolate ChL11 exhibited maximum L-ASNase production in sucrose and L-asparagine (64.2 ± 0.08^a U/ml and 63.6 ± 0.01^a U/ml, respectively), after 120 h of incubation at 35°C.

Conclusions

The fungal isolates T. asahii isolate ChL11 and C. palmioleophila isolate JK12 have been identified as promising L-ASNase sources of safer therapeutic prospects in cancer therapy due to the reduced GLNase co-activity.

How to cite: Sisay T, Mobegi VA, Wachira S, et al. Isolation and characterization of fungi producing L-asparaginase with reduced L-glutaminase activity from soil samples. Electron J Biotechnol 2024. https://doi.org/10.1016/j.ejbt.2024.05.002.

Background

The important challenge to the biotechnology is to find new effective fusion partners that enable to improve solubility, expression, and optimize the subsequent fine purification of the target protein.

Results

The most invariant part of the most immunogenic region of the surface virulence factor A of Streptococcus pneumoniae was selected as a model target protein, while the thermostable chemotaxis polypeptide of W-type from Thermotoga petrophila was used as a fusion partner. The genes encoding fusion variants of these proteins were constructed and cloned into a plasmid vector under the control of the strong bacteriophage T7 transcription regulatory system. Effective Escherichia coli producer strains were obtained, and optimal conditions were chosen for the production of resulting constructs. The optimal pH and temperature ranges of recombinant proteins were determined, and three-dimensional shapes of their molecules were also predicted. Methods of low-stage protein purification were improved. Some of the isolated proteins demonstrated a high level of expression, solubility and purity.

Conclusions

Novel chimeric proteins were obtained which had not previously been observed in nature in such domain combinations. It was shown that the biotechnologically valuable characteristics of the hybrid proteins were more marked when the thermal-resistant partner was combined with the N-terminus of pneumococcal protein. The principles of their low-stage purification were performed which does not require any special equipment. That is a basis for significant reduction of prices for diagnostic test-systems components and subunit vaccine production.

How to cite: Grishin DV, Sidorov NG, Parfenova OK, et al. Construction, heterological expression and a simple purification of the BP region of the pneumococcal surface protein a fused in different orientations to the chemotaxis adaptor protein CheW from Thermotoga petrophila. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.05.001.

Background

Chinese hamster ovarian (CHO) cells are widely employed in biotechnology for the production of recombinant proteins. Extending the life span of CHO cells and inhibiting the loss of producing cell population through the inhibition of apoptosis can benefit the productivity of those cells. In this study, we aimed to screen and evaluate the impact of some caspase-7 inhibitor candidates on the lifespan of CHO cells.

Results

Through virtual screening and molecular docking, risperidone was screened and selected as a potential inhibitor of caspase-7 in CHO cells. The results of MTT assay revealed that the cytotoxicity of risperidone at all concentrations was lower than 50%, and thus it can be suggested as a safe treatment for CHO cells. Annexin V apoptosis and flow cytometry assays revealed that risperidone at 1, 25, and 50 µM concentrations inhibited apoptosis 72 h post-treatment through caspase-7 inhibition. Although gene expression analysis through qRT-PCR demonstrates that risperidone did not affect caspase-7 gene expression.

Conclusions

This bioinformatics and experimental study suggests risperidone as a caspase-7 inhibitor with the potential to extend the lifespan of CHO cells and offers possible opportunities in biotechnology.

How to cite: Kafi S, Najafi S, Mahnam K, et al. Virtual screening and experimental analysis of caspase-7 inhibitors as candidates for extending the lifespan of CHO cells. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.04.007.

Background

To explore the efficacy of powder of ginsengporia and atractylodis macrocephalae combined with aerobic exercise in the treatment of obese T2DM and its influence on glucose and lipid metabolism indices.

Results

Both groups of patients were given metformin drug treatment. The control group was given aerobic exercise intervention, and the observation group was given ginsengporia and atractylodis macrocephalae on the basis of the control group. The total effective rate of the observation group (95.74%) was higher than that of the control group (82.98%) (P < 0.05). After treatment, the main symptoms of the observation group were less (P < 0.05), such as thirst and lack of desire to drink, fatigue, loss of appetite, limb numbness and tingling, sticky stool, scanty dark urine, and lower total score. FPG, 2hPG, and HbA1c were lower (P < 0.05), FINS, HOMA-IR, and HOMA-β were higher (P < 0.05), TG, TC, and LDL-C were lower, and HDL-C levels were higher in the observation group (P < 0.05). After treatment, Nesfatin-1 and adiponectin were lower, visfatin and leptin were higher (P < 0.05), and GIP and GLP-1 levels were higher in the observation group (P < 0.05). No significant difference was found in the incidence of adverse reactions between the two groups (P > 0.05).

Conclusions

Powder of ginsengporia and atractylodis macrocephalae combined with aerobic exercise is effective in treating obese T2DM, which can alleviate clinical symptoms and the disorder of glucose and lipid metabolism, and improve the islet function and gastrointestinal function.

How to cite: Liu G, Kanti Das S. Efficacy of powder of ginsengporia and atractylodis macrocephalae combined with aerobic exercise in the treatment of obese T2DM: A randomized controlled clinical trial. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.04.006.

Background

The Pacific white shrimp is one of the world’s most economically significant aquatic species, being one of the top three species cultured globally. However, the increasing incidence of diseases such as acute hepatopancreatic necrosis disease and hepatopancreatic microsporidia has led to a serious decline in shrimp production and severe economic losses. With the increasing demand for pathogen detection in shrimp farms, rapid DNA extraction technology has become more sophisticated. In this study, a rapid and crude method of extracting genomic DNA from shrimp muscle and hepatopancreas using Chelex-100 was established.

Results

DNA was successfully extracted from muscle and hepatopancreatic tissues using both the Chelex-100 method and commercial kits. The internal reference genes of shrimp were successfully amplified via PCR and real-time PCR using the obtained DNA samples. Moreover, a field assay was successfully conducted using real-time PCR and real-time enzymatic recombinase amplification (real-time ERA), indicating that the quality of the DNA extracted using Chelex-100 is sufficient for use in conjunction with nucleic acid amplification to detect pathogens in shrimps.

Conclusions

Chelex-100 is an efficient method for extracting DNA from shrimp muscle or hepatopancreas tissues, with a short extraction time, high extraction efficiency, and simple operation, making it appropriate for use in the detection of pathogens in shrimp.

How to cite: Yang H, Zhou Q, Hu J, et al. A Chelex-100-based rapid DNA extraction method and its application in the detection of shrimp pathogens. Electron J Biotechnol 2024;70. https://doi.org/10.1016/j.ejbt.2024.04.004.

Background

The lack of reference genes makes it difficult to conduct molecular biology research on the plant genus, Clematis L. Clematis lanuginosa belongs to Sect. Viticella DC of Clematis L. It is also an important ornamental cultivated variety parent of the early and late large-flowered groups. Studying the reference genes of C. lanuginosa in different tissues will provide a theoretical basis for the reference selection of early and late large-flowered groups of Clematis, which could promote research progress on molecular biology of ornamental Clematis.

Results

The roots, stems, leaves, sepals, stamens, and carpels of C. lanuginosa were used as research materials, and seven candidate reference genes were used for quantitative real-time PCR analysis. Comprehensive stability analysis using geNorm, NormFinder, BestKeeper, and RefFinder software showed that suitable reference genes in C. lanuginosa root, stem, and leaf were PP2A-2 and UBC34; and in floral tissue were UBC34, PP2A-2, and ARP7. These reference genes can be used as internal reference either alone or in combination. The pairwise variation value evaluated with geNorm software showed that two internal reference genes were needed for gene expression correction in the tissues. In the floral organs, three reference genes were required for gene expression correction.

Conclusions

Our results provide a foundation for future gene expression analysis of C. lanuginosa and guidance for the screening of reference genes in Clematis.

How to cite: Li Q, Wang S, Lv F, et al. Selection and validation of reference genes for quantitative real-time PCR in different tissues of Clematis lanuginosa. Electron J Biotechnol 2024;70. https://doi.org/10.1016/j.ejbt.2024.04.005.

Background

Cold damage of maize during germination is a global problem; it occurs frequently in northeast China, and leads to a large-scale reduction in yield. Low temperature tolerance of maize in germination is a complex quantitative trait controlled by multigenes, and no major QTLs or key genes have been identified.

Results

An F₂ isolation population with S319 and R144 as parents was constructed. The bulked segregant analysis (BSA) and specific-locus amplified fragment-sequencing (SLAF-seq) methods were applied to locate the chromosomal association regions related to low-temperature tolerance of maize during germination. Sequencing obtained 221.72 Gbp clean data, with an average sequencing depth of 25.96X. Four candidate regions associated with low-temperature tolerance trait of maize in germination were obtained, with a total length of 25.71 Mb and 1513 annotated genes, including 456 nonsynonymous mutant genes and 111 frameshift mutant genes.

Conclusions

This study aimed to lay the foundation for the mining of candidate genes of low-temperature tolerance in maize during germination, and accelerate the process of targeted improvement of maize low-temperature tolerance molecular marker-assisted breeding.

How to cite: Yu T, Zhang J, Cao J, et al. QTL analysis of low temperature tolerance in maize germination by SLAF-seq and BSA technique. Electron J Biotechnol 2024;70. https://doi.org/10.1016/j.ejbt.2024.04.003.

Background

Cancer continues to be one of the greatest challenges in modern medicine and is second only to cardiovascular disease as the main cause of death. Breast cancer in particular is responsible for 15% of deaths in women. In this study, Lactobacillus bulgaricus was microencapsulated using a chitosan/alginate mixture. Parameters such as chitosan, alginate, and L. bulgaricus populations were optimized using Design Expert software. The responses were loading efficiency, particle size, release, and ζ-potential. Subsequently, the cytotoxicity of the optimized ratio of chitosan/alginate nanoparticles was investigated on MCF-7 cancer cells.

Results

The research revealed that optimal conditions for the mentioned variables were a chitosan concentration of 1% w/w, an alginate concentration of 1% w/w, and a L. bulgaricus count of 8.15 CFU/ml. Following numerical optimization, the loading efficacy = 91.15%, the release = 71.55%, the polydispersity index = 0.11, and the ζ-potential = 61.94 based on numerical optimization. Findings revealed that miracle drinks with L. bulgaricus-loaded chitosan/alginate microcapsule ratios exhibited toxic and potential apoptotic effects on MCF-7 cancer cells. This study showed that a miracle drink prepared with the optimal ratio of probiotic nanoparticles stops cells in the S and G2/M phases.

Conclusions

The results show that Miracle drink supplemented with L. bulgaricus loaded-chitosan/alginate nanoparticles has a toxic and lethal effect on MCF-7 cancer cells. This compound can be suggested and used as an alternative candidate or complementary cancer therapy.

How to cite: Jovaini K, Mortazavian Farsani SAM, Aghaee-Bakhtiari SH, et al. Miracle drink supplemented with L.bulgaricus loaded-chitosan/alginate nanoparticles as a medicinal food for control of MCF7 cancer cells. Electron J Biotechnol 2024;69. https://doi.org/10.1016/j.ejbt.2024.04.002.

Background

Coffee fermentation process influences the final coffee composition and the sensory aspects which define the quality of the beverage. In this study, coffee fruits underwent spontaneous self-induced anaerobic fermentation using samples with two percentages of immature fruits in submerged and solid-state processing. The effects on the physicochemical composition and sensory quality of coffees were evaluated.

Results

The two percentages of immature fruits corresponded to 11.0 and 0.3% of unripe fruits. The percentage of immature fruits significantly altered the initial content of sugars (sucrose, glucose, and fructose), ash, and titratable acidity. The water addition during the fermentative process did not significantly influence final moisture, proteins, citric acid, and propionic acid concentrations. Compared to the solid-state, the submerged process gave rise to coffees with lower concentrations of ethanol, glycerol, ash, lipids, succinic, and acetic acids. Coffee fermented with 0.3% of immature fruits showed higher lactic acid production in submerged fermentation (67.44 mg/g), and higher concentrations of ethanol (42.84 mg/g) and glycerol (1.68 mg/g) in solid-state fermentation. All coffees produced were classified as specialty coffees with a score above 84 points. However, the submerged fermented coffee with 11% immature fruit stood out with notes of caramel, brown sugar, honey, orange, lemon, floral, nut, yellow and red fruits.

Conclusions

This study confirmed that spontaneous fermentation can be used to produce specialty coffees. Differentiation in sensory attributes can be achieved through the addition of water and varying the percentage of green fruits during the fermentation process. Up to 11% of immature fruits did not compromise coffee quality.

How to cite: Ferreira LJC, Casé IN, Bertarini PLL, et al. Impact of immature coffee fruits and water addition during spontaneous fermentation process: Chemical composition and sensory profile. Electron J Biotechnol 2024;69. https://doi.org/10.1016/j.ejbt.2024.04.001.