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Whole-genome sequencing and genome mining are recently considered an efficient approach to shine more light on the underlying secondary metabolites of Streptomyces. The present study unearths the biosynthetic potential of endophytic SX6 as a promising source of biologically active substances and plant-derived compounds for the first time. Out of 38 isolates associated with Aegiceras corniculatum (L.) Blanco, Streptomyces parvulus SX6 was highly active against Pseudomonas aeruginosa ATCC® 9027™ and methicillin-resistant Staphylococcus epidermidis (MRSE) ATCC® 35984™. Additionally, S. parvulus SX6 culture extract showed strong cytotoxicity against Hep3B, MCF-7, and A549 cell lines at a concentration of 30 μg/ml, but not in non-cancerous HEK-293 cells. The genome contained 7.69 Mb in size with an average G + C content of 72.8% and consisted of 6,779 protein-coding genes. AntiSMASH analysis resulted in the identification of 29 biosynthetic gene clusters (BGCs) for secondary metabolites. Among them, 4 BGCs showed low similarity (28–67% of genes show similarity) to actinomycin, streptovaricin, and polyoxypeptin gene clusters, possibly attributed to antibacterial and anticancer activities observed. In addition, the complete biosynthetic pathways of plant-derived compounds, including daidzein and genistein were identified using genome mining and HPLC-DAD-MS analysis. These findings portray an exciting avenue for future characterization of promising secondary metabolites from mangrove endophytic S. parvulus.

Textile industry effluents contain several hazardous substances, such as dye-containing effluents, which pose environmental and aesthetic challenges. Presently, the microbial-based remediation process is in use. This study investigated the application of ferrous–ferric oxide (Fe3O4) nanoparticles, a readily formulated nanoadsorbent, to remove scattered dye molecules from industrial effluents. The ferrous–ferric oxide nanoparticles were prepared using a chemical co-precipitation method. The nanoparticles had 26.93 emu g−1 magnetization, with sizes smaller than 20 nm, and possessed a highly purified cubic spinel crystallite structure. The catalytic activity of the iron oxide depended on the dose, photocatalytic enhancer, i.e., H2O2 level, pH of the reaction medium, and dye concentration. We optimized the Fenton-like reaction to work best using 1.0 g/L of ferrous–ferric oxide nanoparticles, 60 mM oxalic acid at pH 7.0, and 60 ppm of dye. Iron oxides act as photocatalysts, and oxalic acid generates electron–hole pairs. Consequently, higher amounts of super-radicals cause the rapid degradation of dye and pseudo-first-order reactions. Liquid chromatography–mass spectrometry (LC-MS) analysis revealed the ferrous–ferric oxide nanoparticles decolorized and destroyed Disperse Red 277 in 180 min under visible light. Hence, complete demineralization is observed using a photo-Fenton-like reaction within 3 h under visible light. These high-capacity, easy-to-separate next-generation adsorption systems are suggested to be suitable for industrial-scale use. Ferrous–ferric oxide nanoparticles with increased adsorption and magnetic properties could be utilized to clean environmental pollution. [ABSTRACT FROM AUTHOR]

The Vietnam sugarcane industry faces to many challenges during the last few years since Covid-19 pandemic. However, the industry has a significant increase in the last 2 years thanks to many factors that make a remarkable transformation of the industry. This paper reviews the factors affecting this significant transformation of the sugarcane industry and toward the trend of net zero and sustainable transformation of sugarcane value chain and sugar industry in Vietnam such as digitalization of the supply chain, research and development of co-products from sugar processing, application of big data and AI in consumer insight of the R&D process. [ABSTRACT FROM AUTHOR]

Amentotaxus yunnanensis H.L.Li is a threatened conifer distributed only in China, Laos, and Vietnam, whose fungal endophytes have not been exploited yet. The aims of this study were to screen and characterize antioxidant metabolites from endophytic fungi obtained from A. yunnanensis. Using the surface sterilization method, sixteen endophytic fungi were isolated from A. yunnanensis and classified into seven genera including Fusarium, Penicillium, Aspergillus, Diaporthe, Neopestalotiopsis, Purpureocillium, and Simplicillium through the analysis of Internal Transcribed Spacer (ITS) gene sequences. Among the ethyl acetate crude extracts, Fusarium foetens AQF6 contained the highest amount of polyphenol (117.76 ± 0.94 mg gallic acid equivalent/g) and flavonoid (169.01 ± 2.09 mg quercetin equivalent/g). Importantly, 400 µg/mL AQF6 extract exhibited 95.75 ± 1.1% and 85.66 ± 1.91% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities, respectively. Chemical investigation led to the isolation and identification of a new bisabolane-type sesquiterpene fusafoetriol (FUS) and 14 known compounds, among which six pure compounds showed free-radical scavenging activity against DPPH and hydroxyl radicals. Under H2O2 stress, the yeast model Saccharomyces cerevisiae treated with 4 mM FUS showed 43.31% increase in viability. FUS has the potential to be applied in nutraceutical, pharmaceutical and food technological applications. Thus, this is the first report demonstrating the presence of endophytic fungi inhabiting A. yunnanensis and their potential as a prolific source of antioxidant metabolites. [ABSTRACT FROM AUTHOR]

The genus Streptomyces is not only known as a natural producer of antibiotics but also a prolific source of chitinolytic enzymes that digest recalcitrant chitin to chitooligosaccharides. However, only a few reports have used whole-genome sequencing to study chitin degradation of Streptomyces to date. In the present study, out of 22 Streptomyces strains, Streptomyces parvulus VCCM 22513 produced the highest chitinase activity. Time courses of incubation revealed that the maximum chitinase (0.91 ± 0.04 U/mL) of this strain was observed after 96 hours in the yeast extract salts medium supplemented with 10.0 g/L colloidal chitin. Additional genomic analysis of VCCM 22513 was also conducted to discover the genomic information related to chitin degradation. The VCCM 22513 genome consists of 341 carbohydrate-active enzyme coding genes divided into 6 families including glycoside hydrolase (134 genes), carbohydrate-binding module (88 genes), glycosyl transferase (87 genes), carbohydrate esterase (18 genes), polysaccharide lyase (7 genes), and auxiliary activity (7 genes). Further genome mining revealed the presence of 10 chitinases, 4 lytic polysaccharide monooxygenases, and 14 β-Nacetylhexosaminidases, which mainly contribute to the degradation of chitin polymers. This is the first report revealing the mechanism underlying the chitin degradation of S. parvulus. Future investigations are required to characterize chitinolytic enzymes found in this study for the bioeconomic production of high-quality chitooligosaccharides from chitin food wastes [ABSTRACT FROM AUTHOR]

Cephalotaxus mannii Hook. f. is a rare evergreen conifer native listed in the International Union for Conservation of Nature (IUCN) Red List, which is utilized for leukemia treatment. Although endophytic fungi from C. mannii was reported before, their cytotoxic property has not been revealed yet. In the present study, a total of 7 endophytic fungi were isolated from C. mannii collected in Ha Giang province, Vietnam, among which the isolate WQF18 was active against 5 tested pathogens with inhibition zones ranging from 18.0 ± 0.7 to 25.0 ± 0.4 mm. In addition, only ethyl acetate extract of isolate WQF18 showed cytotoxicity on A549 and MCF7 cell lines with IC50 values of 69.6 ± 2.3 µg/mL and 78.6 ± 1.6 µg/mL, respectively. PCR-based molecular screening revealed that the positive hits for both 10-deacetylbaccatin III-10-O-acetyl transferase (dbat) and taxadiene synthase (ts) genes involved in paclitaxel biosynthesis were only observed in the WQF18 isolate. Based on morphological and molecular identification, the WQF18 isolate was identified as Talaromyces wortmannii WQF18. The presence of paclitaxel in T. wortmannii WQF18 was further confirmed by dbat sequence alignment, phenotypic, and HPLC-DAD analysis. To the best of our knowledge, this is the first report demonstrating the paclitaxel-producing capability of endophytic fungi from C. mannii. These findings provide a new platform for deciphering paclitaxel biosynthesis of endophytic fungi from non-Taxus plants and further paclitaxel production. [ABSTRACT FROM AUTHOR]

Cephalotaxus mannii Hook.f is a rare medicinal plant used for the treatment of leukemia, however, its fungal endophytes with antibacterial and anticancer properties have not been exploited yet. In this study, six fungal isolates were recovered from roots of C. mannii collected in Ha Giang province, Vietnam. Among them, ethyl acetate crude extract of strain WQF5 exhibited strong antibacterial activity against 5 tested pathogens with inhibition zones ranging from 13.0 ± 0.5 mm to 20.0 ± 0.4 mm. Sulforhodamine B assay showed that WQF5 extract possessed the most potent cytotoxic activity against lung cancer A549 and breast cancer MCF7 cell lines with IC50 values of 6.9 ± 0.7 μg/mL and 23.1 ± 1.9 μg/mL, respectively. PCR-based molecular marker screening revealed that the positive hits for essential genes encoding 10- deacetylbaccatin III-10-O-acetyltransferase (dbat) and C-13 phenylpropanoyl side chain-CoA acyltransferase (bapt) involved in paclitaxel production were found in the fungal isolate WQF5. In addition, isolate WQF5, identified as Fusarium fujikuroi by morphological and ITS analysis, also produced paclitaxel as shown by HPLC-DAD analysis. This is the first report of bioprospecting endophytic fungi isolated from C. mannii, in which the capability of producing paclitaxel of endophytic fungi was also proved for the first time. These findings addressed a potent candidate for paclitaxel production and provided excellent material for further investigations of how endophytic fungi from non-Taxus plant species synthesize paclitaxel. [ABSTRACT FROM AUTHOR]

Sugarcane is one of the most important industrial crops in Vietnam and covers a total of 127,000 hectares of plantation area. In the season 2020–2021, Vietnam has produced 0.763 million tons of sugar (accounting for 0.34% total world sugar production). A current sugarcane production of 7.498 million tons is being used mainly for sugar production for direct consumption, ethanol production, bio-electricity and fertilization. To ensure crop sustainability, various policies and plans have been implemented. Crop breeding and zoning improvement programme significantly influence sugarcane production and sugar yield. Over 25 years since the programme "one million ton of sugar" was promoted, Vietnam currently possesses 25 sugar mills with a total capacity of 110,000 tons of sugarcane per day. Major problems of sugarcane industry as well as research and development have been discussed in this review. Recent research and development work focused on the added values of co-products to ensure sustainability of the sugarcane industry. Molasses will be used for ethanol production, and bagasse is used as the biomass for the alternative energy. Sugarcane and sugar would be the main feedstocks for those bio-economy growths in Vietnam. To keep the sustainable development of the sugar industry, and to meet the demand of the food and non-food requirements, it is necessary to upgrade the sugar value chain through the adoption and the development of co-products of the sugar industry. [ABSTRACT FROM AUTHOR]

Mangrove endophytes have recently gained considerable attention due to their diversity and abundance of novel bioactive secondary metabolites. Despite the fact that Streptomyces species are producers of more than 75% of commercialized antibiotics, Streptomyces associated with the extremely widespread mangrove plant Avicennia marina remain poorly characterized. In this study, nine actinomycetes were isolated from A. marina growing in a mangrove forest, as yet unexplored, of Quang Ninh province, Vietnam. Phylogenetic analysis of actinomycetes-specific 16S rRNA sequences indicated that they were subjected to five Streptomyces species including Streptomyces cacaoi, Streptomyces californicus, Streptomyces enissocaesillis, Streptomyces coelicoflavus, and Streptomyces variabilis, which have not been previously reported in mangrove plants. Among them, S. cacaoi AM1 showed strong inhibition effects against six tested pathogenic bacteria with inhibitory zones ranging from 7.5-22.3 mm. Using standard 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, 100 µg/mL ethyl acetate extract of AM1 showed potent cytotoxicity against breast cancer MCF-7 and lung cancer A549 cell lines with cell viability of 16.5 ± 1.28% and 17.69 ± 2.3%, respectively. As for antioxidant activities, AM1 extract exhibited strong antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical (92.4 ± 0.004%) and superoxide anion radical (42.4 ± 0.019%), which were positively correlated to high polyphenol (84.3 ± 3.4 µg GAE/g FW) and flavonoid (34.9 ± 4.8 µg QE/g FW) contents. These findings indicated that S. cacaoi AM1 could be a promising reservoir of antibacterial, anticancer, and antioxidant agents. This is the first report of mangrove endophytic Streptomyces derived from A. marina. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria have been advocated as probiotics to replace antibiotic growth promoters, improve growth performance, and reduce cost production in swine farming. The aim of this study is to identify and evaluate the probiotic traits of strain LCN13 isolated from traditionally fermented feed for swine. Thirty-five bacterial isolates with different morphological characteristics were isolated, among which 9 isolates showed the ability to produce lactic acid and antibacterial activity against pathogenic bacteria. Among them, isolate LCN13 exhibited a strong capacity to produce lactic acid (18.5 ± 0.31 g/L), inhibited gastrointestinal pathogens such as Salmonella typhimurium ATCC 14028 (18.3 ± 1.52 mm), Escherichia coli ATCC 11105 (24.7 ± 2.14 mm), and Staphylococcus epidermidis ATCC 35984 (31.6 ± 2.93 mm), and produced 182 ng/mL folate and 233 ng/mL riboflavin as measured by LC-MS/MS after 24 hours of incubation. Based on morphological, biochemical, and 16S rRNA gene analysis, the isolate LCN13 was identified as Lactobacillus plantarum. Phenotypic analysis revealed that L. plantarum LCN13 showed remarkable resistance to 1.2% ox-bile salt, 2.0 mM H2O2, and pH 3.0. In addition, the ability to produce high levels of folate (253.6 ± 10.7 ng/mL) and riboflavin (312.0 ± 12.2 ng/mL) after 48 hours was exploited for the first time in the L. plantarum. Taken together, L. plantarum LCN13 might serve as a potential probiotic candidate for animal farming. [ABSTRACT FROM AUTHOR]

B-vitamins are micronutrients that play an important role in various cellular processes of organisms, which are only synthesized by plants, yeasts, and bacteria. Since animals and humans lack the ability to synthesize B-vitamins, supplements of vitamins from dietary and the B-vitamin producing bacteria are required. In this study, we, for the first time, shed some light on biosynthetic pathways involved in folate (vitamin B9), riboflavin (vitamin B2), and biotin (vitamin B7) production in Bacillus velezensis VTX20. The genome-wide comparison revealed that B. velezensis VTX20 shared high similarities with B. tequilensis KCTC 13622, B. subtilis 168, B. amyloliquefaciens DSM 7. Genomic analysis revealed the presence of a complete folate biosynthesis pathway in which some core components were not found in most Bacillus species. Moreover, strain VTX20 also had the metabolic pathways for riboflavin and biotin that are important probiotic traits. These results highlighted that B. velezensis VTX20 is a producer of Bvitamins, which can be applied further in the agricultural biotechnology industry. [ABSTRACT FROM AUTHOR]

Exopolysaccharides (EPSs) produced by Bacillus species have recently emerged as promising commercial antioxidants in various industries, such as pharmaceutics and biomedicine. However, little is known about EPS production and function from Bacillus velezensis so far. In the present study, the effect of sugar sources on EPS production by B. velezensis VTX20 and the genetic biosynthesis, characteristics, and antioxidant activity of the resulting EPS were evaluated. The strain VTX20 produced the maximum EPS yield of 75.5 ± 4.8 g/L from an initial 200 g/L of sucrose after a 48-h cultivation. Through genomic analysis, ls-levB operon was found, for the first time, to be responsible for the levan-type EPS production in B. velezensis. Biochemical and structural characterization further confirmed the majority of levan, followed by an extremely low level of dextran biopolymer. The water solubility index and water holding capacity of the EPSs were 81.9 ± 3.4% and 100.2 ± 3.4%, respectively. In vitro antioxidant activity analyses showed strong scavenging activity for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical values of 40.1–64.0% and 16.0–40%, respectively. These findings shed light on the EPS biosynthesis of B. velezensis at both structural and genetic levels and the potential application of EPS as a natural antioxidant for pharmaceutical and biomedical industries. [ABSTRACT FROM AUTHOR]

Fungi are the most harmful microorganisms responsible for the deterioration of nonmetallic materials such as glass, polymers, and composites. To date, biological aspects of glass deterioration have been poorly investigated. The present study aimed to evaluate the diversity of the fungal community colonizing eyepieces of binoculars collected from museums of the northern provinces of Vietnam and the biodeterioration effects on accurate glass reproductions. A total of 40 isolates belonging to 14 genera were identified based on internal transcribed spacer (ITS) sequencing, morphological features, and maximum likelihood analysis. The most abundant fungal genera included Aspergillus (43.8%) and Penicillium (31.3%). Among those detected, Byssochlamys, Curvularia, Phomopsis, Coprinellus, Perenniporia, Talaromyces, Pithomyces, Neopestalotiopsis, Trichoderma, Pleospora, and Humicola were found for the first time. Of the 40 strains tested, 8 strains showed great organic acid production, and the extent of mycelium covered from 33.6 to 46.24%. Specifically, the highest extracellular polymeric substance production was observed in Byssochlamys spectabilis BXMA1-2 (14.96 g/L), Aspergillus niger BXMA5-2 (12.17 g/L), and Aspergillus ochraceopetaliformis BMLC1-2 (9.89 g/L). Glass biodeterioration experiments revealed that the light transmission through the fungal-treated glasses was decreased by 30–42.2% as compared to the nontreated glass. In addition, the main alterations resulted from hyphal fingerprints and spots, leading to apparent damage and biocorrosion. [ABSTRACT FROM AUTHOR]

Dracaena cochinchinensis Lour. is an ethnomedicinally important plant used in traditional Chinese medicine known as dragon’s blood. Excessive utilization of the plant for extraction of dragon’s blood had resulted in the destruction of the important niche. During a study to provide a sustainable way of utilizing the resources, the endophytic Actinobacteria associated with the plant were explored for potential utilization of their medicinal properties. Three hundred and four endophytic Actinobacteria belonging to the genera Streptomyces, Nocardiopsis, Brevibacterium, Microbacterium, Tsukamurella, Arthrobacter, Brachybacterium, Nocardia, Rhodococcus, Kocuria, Nocardioides, and Pseudonocardia were isolated from different tissues of D. cochinchinensis Lour. Of these, 17 strains having antimicrobial and anthracyclines-producing activities were further selected for screening of antifungal and cytotoxic activities against two human cancer cell lines, MCF-7 and Hep G2. Ten of these selected endophytic Actinobacteria showed antifungal activities against at least one of the fungal pathogens, of which three strains exhibited cytotoxic activities with IC50-values ranging between 3 and 33 μg·mL−1. Frequencies for the presence of biosynthetic genes, polyketide synthase- (PKS-) I, PKS-II, and nonribosomal peptide synthetase (NRPS) among these 17 selected bioactive Actinobacteria were 29.4%, 70.6%, and 23.5%, respectively. The results indicated that the medicinal plant D. cochinchinensis Lour. is a good niche of biologically important metabolites-producing Actinobacteria. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the synergistic effects of the crude ethyl acetate extract (CEAE) from endophytic actinomycete MPT42 and essential oil (EO) of the same host plant Litsea cubeba. The isolate MPT42, exhibiting broad-spectrum antimicrobial activities and harboring all three antibiotic-related biosynthetic genes pks-I, pks-II, and nrps, was identified as Streptomycete griseorubens based on an analysis of the morphology, physiology, and 16S rDNA sequence. Minimum inhibitory concentrations (MICs) and the fractional inhibitory concentration index were used to estimate the synergistic effects of various combined ratios between CEAE or antibiotics (erythromycin, vancomycin) and EO toward 13 microbial strains including pathogens. L. cubeba fruit EO, showing the main chemical constituents of 36.0% citral, 29.6% carveol, and 20.5% limonene, revealed an active-low against tested microbes (MICs ≥ 600 μg/mL). The CEAE of S. griseorubens culture exhibited moderate–strong antimicrobial activities against microbes (MICs = 80–600 μg/mL). Analysis of the mechanism of action of EO on Escherichia coli ATCC 25922 found that bacterial cells were dead after 7 h of the EO treatment at 1 MIC (5.5 mg/mL), where 62% cells were permeabilized after 2 h and 3% of them were filament (length ≥ 6 μm). Combinations of CEAE, erythromycin, or vancomycin with EO led to significant synergistic antimicrobial effects against microbes with 4–16 fold reduction in MIC values when compared to their single use. Interestingly, the vancomycin–EO combinations exhibited a strong synergistic effect against five Gram-negative bacterial species. This could assume that the synergy was possibly due to increasing the cell membrane permeability by the EO acting on the bacterial cells, which allows the uptake and diffusion of antimicrobial substances inside the cell easily. These findings in the present study therefore propose a possible alternative to combat the emergence of multidrug-resistant microbes in veterinary and clinics. [ABSTRACT FROM AUTHOR]

Huperzine A (HupA) and huperzine B (HupB) are potent acetylcholinesterase inhibitor used widely for clinical treatment of Alzheimer’s disease, which are mainly extracrted from natural populations of Huperzia species. This study aimed to the evaluate potential of producing Hup of native Huperzia javanica species collected in Vietnam as well as identify endophytic fungi that produce high Hup or simultaneously produce many types of Hup derived from this plant as a material source for natural Hup production. By HPLC–DAD-MS analysis, H. javanica collected from Ha Giang, Vietnam was found as a novel producer of HupA and HupB with a yield of 0.513 mg/g dry weight (wt) and 0.192 mg/g dry wt, respectively. Inspired by this discovery, a total of 63 endophytic fungi were isolated from healthy tissues of the collected H. javanica plants, including 52 fungal strains belonging to nine genera and 11 unidentified strains based on morphological characteristics. Using HPLC, 9 Hup-producing fungi were identified when compared to the standard HupA and HupB. Surprisingly, 7 fungal strains produced both HupA and HupB, among which strain TLC12 produced the highest HupA and HupB contents of 0.271 and 0.163 mg/g mycelium dry cell weight (gdcw), respectively. Fungal strains TLC19 and TLC22 only yielded a respective amount of 0.305 and 0.135 mg/ gdcw of HupA. Combining with Internal Transcribed Spacer sequence analysis, 9 potent fungi were identified as Neurospora calospora (TLC9, TLC10, TLC11), Schizophyllum commune TLC12, Epicoccum sorghinum TLC13, Alternaria tenuissima TLC14, Cephalotrichum sp. TLC20, Daldinia sp. TLC19, and Schizophyllum sp. TLC22. To the best of our knowledge, this is the first report demonstrating H. javanica as a prolific and novel source of endophytic fungi capable of yielding high HupA and HupB contents. The exploitation of 9 Hup-producing fungi is also valuable for both basic research and industrial Hup manufactures. These findings open new perspectives for industrial production of fungal HupA and HupB and conservation of Huperzia species. [ABSTRACT FROM AUTHOR]