Insights into the novel Enterococcus faecalis phage: A comprehensive genome analysis.

Enterococcus faecalis, a Gram-positive bacterium, poses a significant clinical challenge owing to its intrinsic resistance to a broad spectrum of antibiotics, warranting urgent exploration of innovative therapeutic strategies. This study investigated the viability of phage therapy as an alternative intervention for antibiotic-resistant E. faecalis, with a specific emphasis on the comprehensive genomic analysis of bacteriophage SAM-E.f 12. The investigation involved whole-genome sequencing of SAM-E.f 12 using Illumina technology, resulting in a robust dataset for detailed genomic characterization. Bioinformatics analyses were employed to predict genes and assign functional annotations. The bacteriophage SAM-E.f 12, which belongs to the Siphoviridae family, exhibited substantial potential, with a burst size of 5.7 PFU/infected cells and a latent period of 20 min. Host range determination experiments demonstrated its effectiveness against clinical E. faecalis strains, positioning SAM-E.f 12 as a precise therapeutic agent. Stability assays underscore resilience across diverse environmental conditions. This study provides a comprehensive understanding of SAM-E.f 12 genomic composition, lytic lifecycle parameters, and practical applications, particularly its efficacy in murine wound models. These results emphasize the promising role of phage therapy, specifically its targeted approach against antibiotic-resistant E. faecalis strains. The nuanced insights derived from this research will contribute to the ongoing pursuit of efficacious phage therapies and offer valuable implications for addressing the clinical challenges associated with E. faecalis infections.

Screening of antagonistic yeast strains for postharvest control of Penicillium expansum causing blue mold decay in table grape.

Blue mold decay caused by Penicillium expansum is one of the most important postharvest diseases of grapes, leading to considerable economic losses. Regarding the increasing demand for pesticide-free foods, this study aimed to find potential yeast strains for biological control of blue mold on table grapes. A total of 50 yeast strains were screened for antagonistic activity against P. expansum using the dual culture method and six strains significantly inhibited the fungal growth. All six yeast strains (Coniochaeta euphorbiae, Auerobasidium mangrovei, Tranzscheliella sp., Geotrichum candidum, Basidioascus persicus, and Cryptococcus podzolicus) reduced the fungal growth (29.6-85.0%) and the decay degree of wounded grape berries inoculated with P. expansum while G. candidum was found to be the most efficient biocontrol agent. On the basis of antagonistic activity, the strains were further characterized by in vitro assays involving inhibition of conidial germination, production of volatile compounds, iron competition, production of hydrolytic enzymes, biofilm-forming capacity, and exhibited three or more putative mechanisms. To our knowledge, the yeasts are reported for the first time as potential biocontrol agents against the blue mold of grapes but more study is required to evaluate their efficiency related to field application.

Saccharomycopsis oxydans sp. nov., a new non-fermentative member in the genus Saccharomycopsis isolated from a traditional dairy product of Iran.

A total of 21 yeast isolates were recovered as part of a research project on biodiversity of yeasts in traditional dairy products in Alborz province, Iran. Standard protocols were used to carry out phenotypic, biochemical, physiological characterization and the phylogenetic analysis of combined the D1/D2 domain of the large ribosomal subunit (26S or LSU) and ITS region sequences. Five strains represented a potential new ascomycetous yeast species. Ascospore formation was not observed in these strains, and they did not ferment the examined carbon sources. Phylogenetic analysis placed these isolates in a well-supported sub-clade in the genus Saccharomycopsis. Here, we describe this novel yeast as Saccharomycopsis oxydans sp. nov.

Aureobasidium mangrovei sp. nov., an ascomycetous species recovered from Hara protected forests in the Persian Gulf, Iran.

A new ascomycetous black yeast-like species was recovered from healthy plant (Avicennia marina) of Hara protected mangrove forests at Qeshm Island, Iran. Morphological, physiological analysis as well as a molecular analysis of the internal transcribed spacer (ITS) and partial large ribosomal subunit (D1/D2 domains) confirmed the placement of this strain in the genus Aureobasidium and based on considerable sequence divergence, distinguishable cardinal growth temperatures and salt tolerance a new species Aureobasidium mangrovei sp. nov. is proposed. However, the type strain micro-morphologically is not clearly distinguishable from other members of the genus. The type strain, Aureobasidium mangrovei was preserved in a metabolically inactive state at the Iranian Biological Resource Centre, Tehran, Iran as IBRC-M 30265T and the ex-type culture is deposited in the CBS yeast collection of the Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands as CBS 142205T. The GenBank accession numbers for the nucleotide sequences of the large subunit ribosomal DNA and ITS region are KY089084 and KY089085, respectively. The MycoBank number of the new species is MB 823444.

Blastobotrys persicus sp. nov., an ascomycetous yeast species isolated from cave soil.

Two strains (AHD129-1T and AHD129-2) of a new anamorphic yeast species were isolated from Mejare cave soil samples of Abdanan, Ilam, Iran. Nucleotide divergence in the D1/D2 domain of the large subunit (LSU) rRNA, and internal transcribed spacer (ITS) genes suggest that the two strains can be assigned to the Trichomonascus/Blastobotrys clade. A maximum likelihood tree based on sequences of the D1/D2 domain revealed that the new species is closely related to the species Trichomonascus ciferrii, Candida allociferrii, and Candida mucifera. The new species could be distinguished from the closely related species by its ability to grow at 42 °C and the inability to assimilate D-arabinose and D-mannitol. The name B. persicus sp. nov. is proposed for the new anamorphic species. The type strain of B. persicus is AHD129-1T = IBRC-M30238T = CBS 14259T, and the Mycobank number is MB 819148.

Jaminaea pallidilutea sp. nov. (Microstromatales), a basidiomycetous yeast isolated from plant material of mangrove forests in Iran.

In the course of an ongoing study aiming to catalogue the natural yeast biodiversity of Iran, a number of yeasts were isolated from plant material collected from mangrove forests on the shoreline of Qeshm Island. Two strains were identified as members of order Microstromatales. Standard phenotypic, biochemical, physiological characterization and a phylogenetic analyses of the combined 26S rRNA gene (D1/D2 domains) and ITS region sequences showed the conspecificity of these isolates and suggest their placement in the genus Jaminaea, close to Jaminaea lanaiensis and Jaminaea angkoriensis. Here, we describe this species as Jaminiaea pallidilutea sp. nov. with IBRC-M 30284T=DSM 104392T=CBS 14684T as the type strain. The Mycobank accession number is MB 819618.

Wickerhamomyces orientalis f.a., sp. nov.: an ascomycetous yeast species belonging to the Wickerhamomyces clade.

Five closely related yeast strains were isolated from soil in Kharg Island, Persian Gulf, Iran, and from fallen fruits in Galle, Sri Lanka, during separate projects. Morphologically, the strains produced white-coloured yeast colonies, with cells that were ovoid to ellipsoidal, making branched, true hyphae and pseudohyphae. Ascospore formation was not observed. Biochemically, the strains were able to ferment d-glucose and weakly ferment d-galactose. The strains could use a wide variety of carbon sources except methanol and hexadecane. Phylogenetic analyses using combined sequences of the small ribosomal subunit and the D1/D2 domains of the LSU, as well as the internal transcribed spacer regions, suggested that these strains belong to the Wickerhamomyces clade and that together they form one strongly supported phylogenetic clade. Differences in their sequences, biochemistry and morphology suggest they are representatives of distinct species of the genus Wickerhamomyces. Therefore, the name Wickerhamomyces orientalis f.a., sp. nov. is proposed to accommodate these novel strains; the type strain is IBRC-M 30103T (=CBS 13306T). The MycoBank number is MB 807323.

Basidioascus persicus sp. nov., a yeast-like species of the order Geminibasidiales isolated from soil.

A novel species of basidiomycetes was isolated from kitchen garden soil in Shahryar city, Tehran province, Iran. Molecular and conventional methods were employed to identify and classify this single isolate. Morphologically, the isolate was considered yeast-like with hyaline and oval cells reproducing by monopolar budding, forming ballistoconidia, hyphae, arthroconidia and didymospores. Basidia and basidiospores resembling those produced by Basidioascus species were observed. Sequencing and Bayesian phylogenetic analysis of rRNA genes and the internal transcribed spacer region revealed its sister relationship to described species of the genus Basidioascus. Assimilation and fermentation tests, cell-wall carbohydrate analysis and enzyme activity tests were performed to provide insight into the metabolism of the isolate. Based on morphology, physiology and phylogeny of rRNA gene sequences, the isolate was shown to represent a novel species of the genus Basidioascus, described as Basidioascus persicus sp. nov. (holotype IBRC P1010180(T) = ex-type IBRC M30078(T) = isotype CBS 12808(T)). The MycoBank number of the novel species is MB 804703. An emended description of the genus Basidioascus is also provided.

Partial Optimization of Endo-1, 4-Β-Xylanase Production by Aureobasidium pullulans Using Agro-Industrial Residues.

UNLABELLED: Objective(s) : Although bacteria and molds are the pioneering microorganisms for production of many enzymes, yet yeasts provide safe and reliable sources of enzymes with applications in food and feed. MATERIALS AND METHODS: Single xylanase producer yeast was isolated from plant residues based on formation of transparent halo zones on xylan agar plates. The isolate showed much greater endo-1, 4-ß-xylanase activity of 2.73 IU/ml after optimization of the initial extrinsic conditions. It was shown that the strain was also able to produce ß-xylosidase (0.179 IU/ml) and α-arabinofuranosidase (0.063 IU/ml). Identification of the isolate was carried out and the endo-1, 4-ß-xylanaseproduction by feeding the yeast cells on agro-industrial residues was optimized using one factor at a time approach. RESULTS: The enzyme producer strain was identified as Aureobasidiumpullulans. Based on the optimization approach, an incubation time of 48 hr at 27°C, inoculum size of 2% (v/v), initial pH value of 4 and agitation rate of 90 rpm were found to be the optimal conditions for achieving maximum yield of the enzyme. Xylan, containing agricultural residues, was evaluated as low-cost alternative carbon source for production of xylanolytic enzymes. The production of xylanase enzyme in media containing wheat bran as the sole carbon source was very similar to that of the medium containing pure beechwoodxylan. CONCLUSION: This finding indicates the feasibility of growing of A. pullulans strain SN090 on wheat bran as an alternate economical substrate in order for reducing the costs of enzyme production and using this fortified agro-industrial byproduct in formulation of animal feed.

Xanthan production by a native strain of X. campestris and evaluation of application in EOR.

In this study, we used a native strain of X. campestris for xanthan production in lab-scale fermentor and the product was recovered with organic solvents and dried. Then we studied the potential usage of our products in different harsh conditions, including heat, pH and salinity treatments. Furthermore, we used 2D-micromodel for microbial oil recovery investigations. According to present experiments, temperature and salt contents did not have a significant influence on rheological behavior of xanthan solutions and these aqueous solutions maintained at least 80% of their primary viscosity. In addition, these solutions were resistant to a broad range of pH variations. Viscosity of the xanthan solution was increased as it was heated over 120 degrees C. Micro-model experiments showed that the most efficient concentration of xanthan for Enhanced Oil Recovery (EOR) is 1000 mg L(-1) and 53% of original oil in place was recovered, which showed remarkable increase comparing to original oil in place that was recovered (31%) from sole water flooding. The same or even better results were obtained from native xanthan, when its properties were compared to those of a commercial sample which was gifted by NIOC.