Electronic Journal of Biotechnology最新文献

Background

Results

Conclusions

Background

Results

Conclusions

Background

Endophytic fungi produce biologically robust metabolites suitable for diverse applications, which support the increasing exploration of these fungi. The study aimed to investigate the in vitro antimicrobial properties of the metabolites of endophytic fungus Aspergillus terreus which isolated from the leaves of Psidium guajava plants while the acute oral toxicity was assessed in vivo.

Results

A. terreus (OR125572) was successfully isolated for the first time from P. guajava. The ethyl acetate extract of A. terreus exhibited antibactericidal effects against Enterobacter aerogenes with a minimum inhibitory concentration of 18.75 mg/ml in contrast to 75.00 ± 0.0, 37.50, and 37.50 mg/ml, respectively against Staphylococcus aureus, Escherichia coli, and Bacillus sphaericus were 75.00 ± 0.0, 37.50, and 37.50 mg/ml, respectively. Analysis of the crude extract obtained from A. terreus by GC-MS revealed a total of 32 distinct compounds. The major components included 1,2-benzenedicarboxylic acid, di-iso-octyl ester; hexyl oxecan-2-one and phenol. The acute oral toxicity study found no symptoms of toxicity and no mortality until the 14th d, suggesting that the LD₅₀ value of A. terreus extract might exceed 1 ml/kg. The group receiving 0.5 ml/kg of A. terreus extract experienced a 42.9% increase in body weight, while administration of varying dosages resulted in a significant reduction in MCV levels. There was also a significant increase in the proportion of monocytes across all treated groups.

Conclusions

The study demonstrated the potential of A. terreus as a source of antimicrobial and other bioactive compounds, with relatively low acute toxicity.

How to cite: Shehabeldine AM, Abdelaziz AM, Abdel-Maksoud MA, et al. Antimicrobial characteristics of endophytic Aspergillus terreus and acute oral toxicity analysis. Electron J Biotechnol 2024;72. https://doi.org/10.1016/j.ejbt.2024.07.003.

Background

Soil salinization is one of the key factors restricting the production of cropland. Once rice is subjected to alkali stress at the bud burst stage, the yield will suffer irreparable serious loss. Compared with salt tolerance, studies on QTL mapping and candidate gene analysis of rice alkali tolerance are limited.

Results

In this study, we used the F_2:3 population derived from the alkali-tolerant cultivar LD21 and the alkali-sensitive cultivar WL138 to construct an alkali-tolerant DNA mixing pool, and the BSA (Bulked Segregation Analysis) method was used for re-sequencing. The main QTL qRSLB9 controlling the relative shoot length of rice under alkali stress was mapped by QTL-seq. The candidate interval was narrowed to 346.5 kb by regional linkage mapping, which containing 6 DEGs screened through transcriptome sequencing. The qRT-PCR and candidate gene sequencing showed that LOC_Os09g24260 was most likely to control relative shoot length (RSL) in rice as a major gene who encodes the WD domain, G-beta repeat domain-containing protein.

Conclusions

Based on these results, LOC_Os09g24260 was the candidate gene of qRSLB9 conferring alkalinity tolerance to rice at the bud burst stage. Our study provides valuable genetic information and materials for breeding new rice varieties with alkalinity tolerance.

How to cite: Wang J, Bian J, Liu L, et al. Screening and analysis of candidate genes conferring alkalinity tolerance in rice (Oryza sativa L.) at the bud burst stage based on QTL-seq and RNA-seq. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.07.002.

Background

Different methods for the extraction of trypsin inhibitors in beans (Phaseolus spp.) were investigated. Two randomised complete laboratory experiments were performed, one on the seeds and one on the pods. In the first, the seeds of common bean variety KIS Marcelijan, breeding line Ref_316 × 498 and runner bean variety Bonela were examined. In the second, the fresh pods of five common beans (three breeding lines, two varieties) were analysed. Four extraction methods were used, including ultrasonic-assisted extraction (UAE) for 15 and 30 min and shaking-assisted extraction for 60 and 180 min.

Results

The results showed a significant increase in trypsin inhibitor activity-related traits in UAE compared to shaking extraction, with the 15 min ultrasonic process showing better efficacy than the one with 30  min duration. In the seed experiment, the breeding line Ref_316 × 498 showed the highest Trypsin Units Inhibited (TUI) and TUI/mg sample after a 15 min UAE. In the pod experiment, the breeding line 228_4aa_ca also showed the highest TUI and TUI/mg sample after a 15 min extraction with UAE. These results underline the potential of UAE to maximise trypsin inhibitor content. In addition, remarkable correlations between TUI, TUI/mg sample and the percentage of trypsin inhibition (%TIn) were observed in both experiments.

Conclusions

These results provide valuable insights into the relationship between bean genetic resources, extraction methods and trypsin inhibitor content in bean pods and seeds and serve as a basis for refining extraction protocols. The study encourages further research on the practical implications of investigated protocols for breeding programmes and agricultural practices.

How to cite: Tavakoli Hasanaklou H, Pipan B, Meglič V, et al. Trypsin inhibitors in seeds and pods of Phaseolus vulgaris/coccineus: A comparative study of shaking and ultrasonic extraction methods. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.05.003.

Background

Using cell lines to explore the function of organic compounds is fundamental in biotechnology. Evaluating new additives intended to improve animal production is challenging due to the complexity and uncertainty of in vivo testing. This study investigated the action of a compound with antioxidant properties using cells from terrestrial (LMH cells line) and aquatic vertebrates (CHSE-214).

Results

The results of our study provide reassuring evidence of the compound’s safety for use in animal production. The compound demonstrated no adverse effects on cell viability, indicating its potential for safe application. Furthermore, the compound’s antioxidant properties were evident, with a 100% recovery in both cell lines when exposed to hydrogen peroxide 0.1 mM. It also effectively reduced cellular ageing caused by metabolic processes, as measured by the TBARS formation in both cell lines, from 5 MDA µM/mg protein to 2.5 MDA µM/mg protein when used at 0.05 or 0.5 g/L. Notably, this action did not increase cell membrane oxidation, further supporting its safety profile.

Conclusions

These findings indicate that the compound has an antioxidant effect and can be used independently or in combination with metabolic stimulants in the diets of production animals. Applying this additive and its possible synergy with other compounds could help reduce oxidative stress and improve growth in animal production. The data generated in this study provide a solid basis for designing diets incorporating this additive to observe improvements in animal production based on activity observed at the cellular level.

How to cite: Olivares- Ferretti P, Maguregui E, Chavez V, et al. Novel antioxidant additive ENTAN molecule for animal production: Evaluation at the cellular level. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.07.001.

Background

Lactobacillus plantarum can produce many secondary metabolites, some of which have antibacterial effects. This study aimed to explore the main antimicrobial metabolites of Lactobacillus plantarum LPZN19.

Results

The results of antibacterial activity after fermentation for different durations showed that the metabolites from the LPZN19 cell-free supernatant (LCFS) after 24 h had the strongest antibacterial activity, which was confirmed by the highest contents of organic acids and fatty acids in the LCFS after 24 h. Lactic acid, phenyllactic acid, malic acid, aspartic acid, dodecanoic acid and propionic acid were the main differentially abundant metabolites. LCFS was separated by semi-preparative liquid chromatography to obtain 4 antibacterial parts, mainly organic acids such as lactic acid, glycolic acid, and citric acid, and fatty acids such as stearic acid, palmitic acid, and octanoic acid. In addition, fatty glycerides and amino acids with antimicrobial activity were included.

Conclusions

Our findings indicate that the main antimicrobial metabolites of L. plantarum LPZN19 include organic acids, fatty acids, fatty glycerides and some amino acids with antimicrobial activity, which not only clarifies the main antimicrobial metabolites of L. plantarum LPZN19 but also provides an effective method for rapid screening of antimicrobial substances.

How to cite: Wang Y, Xu Y. Analysis and identification of the main antimicrobial metabolites of Lactobacillus plantarum LPZN19. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.05.005.

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.