Aureobasidium Sp Research Articles

GC–MS-based metabolite fingerprinting reveals the presence of novel anticancer compounds in the microcolonial fungus Aureobasidium sp. TD-062 from the under-explored Thar Desert

Aureobasidium sp., strain TD-062, a micro colonial black yeast, was obtained as part of a screening program from the Thar Desert of India, which has been inadequately explored for novel microorganisms/bioactive metabolites. The anticancer activity of aqueous and organic solvent extracts of culture supernatant of TD-062 was investigated against A-375 myeloma and MCF-7 breast cancer cell lines. Following column chromatography, bioactive fractions were subjected to GC–MS analysis in two cycles. The GC–MS metabolite fingerprinting revealed 20 compounds belonging to various chemical groups. Further, based on observed and calculated mass ion spectra, retention time, and retention indices, many compounds could be considered novel. The second purification cycle resulted in three compounds- ATD-1, ATD-2 and ATD-3 with different calculated retention indices from that of the nearest matching compounds, squalene and tocopherol. In silico prediction study of their ADMET profiles, suggests that these new compounds have a suitable contour for use as safe anticancer drugs, without the toxicity normally associated with anticancer compounds.

Chemical Constituents from the deep-sea-derived Fungus Aureobasidium melanogenum LUO5.

Three new C10 and C12 aliphatic δ-lactones (1-3), three new fatty acid methyl esters (4-6), and eight known compounds (7-14) were isolated from the marine Aureobasidium sp. LUO5. Their structures were established by detailed analyses of the NMR, HRESIMS, optical rotation, and ECD data. All isolates were tested for their inhibitory effects on nitric oxide production in LPS-induced BV-2 cells. Notably, compound 4 displayed the strongest inhibitory effect with the IC50 value of 120.3 nM.

The potential of dark septate endhophyte fungus from white jabon (Neolamarckia cadamba (Roxb.) Bosser)

Endophytic fungi are one of the forest microbes that can be solutions for increasing the resistance of forest plants to environmental stress. Exploration and collection of endophytic fungi from the forest is important because the condition of the forest as a natural habitat for microbes has been disturbed due to degradation and deforestation. A potential plant species for forest and land rehabilitation is white jabon (Neolamarckia cadamba (Roxb.) Bosser). The research objective was to isolate and characterize endophytic fungi and to obtain the dark septate endhophyte from the roots of the white jabon which have the potential to increase plant growth. The fungus was isolated by surface sterilization method and then characterized and identified morphologically. Pathogenicity test was carried out to determine the pathogenicity of the fungus. The results of the study found ten isolates. Most of the isolated fungi showed sterile mycelia with septate hyphae, so they were not identified morphologically. The isolate of CPGS 3 isolates probably belonged to the genus Aureobasidium sp. CPGS 3, CPKR 6, and CPPS 11 isolates are candidates for dark septate endophyte fungi which have the potential to promote plant growth and not become pathogens in chinese cabbage (Brassica rapa).

Yeast species of diverse functionality in health sciences: A concise report

The health of a living being is of paramount importance in productivity, which may be human productivity, animal productivity, crop plant productivity, or aquaculture productivity. Among the several pathogenic entities responsible to affect health, yeast is emerging as an important pathogen, while on the other hand; it is also being used as a probiotic agent in treating certain diseases of human and animals. These single-cell budding microorganisms are inhabitant of soil, water, and environment, and are associated with decomposing and fermenting material, living being, and agricultural crops and produce. These are specific in their association, activities, and role and belong to different genera/species. The most common yeast species that act as agents of human disease are species of Candida particularly Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. Similarly, the most evident emerging yeast pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. The yeast responsible for animal infection and diseases mostly belongs to Candida species, the most important being C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and C.krusei besides some other candida species to cause various types of infectious diseases in animals. Cryptococcus neoformis and Cryptococcus gattii are other two important yeast of the Cryptococcus genus implicated in animal diseases. Other cryptococcus species like C. laurentii and C. albidus affect immunocompromised animals. The yeast Malassezia is also reported to cause disease in animals. Bird’s infections are mostly reported to cause by species of Candida. The yeast species useful as probiotics in the treatment of human health ailments includes Saccharomyces boulardii, while in the use of animal and poultry health is Saccharomyces cerevisiae. The yeast species known to cause disease infection in Marine animals include the ascomycetous yeasts which comprise 9 known species from four genera (viz. Candida, Meyerozyma, Kodamaea, and Wickerhamomyces), and the basidiomycetous yeasts comprises 10 known species from eight genera (viz. Vishniacozyma, Filobasidium, Naganishia, Papiliotrema, Sterigmatomyces, Cystobasidium, Rhodotorula, and Rhodosporidiobolus). The species with the highest occurrence is Rhodotorula mucilaginosa. The yeast species involved in plant growth-promoting activities directly or indirectly includes the species of Candida, Rhodotorula, Saccharomyces, Geotrichum, Williopsis, Hanseniaspora, Meyerozyma, Torulaspora, Trichosporon, Pichia, Debaryomyces, Lachanceae and Rhodosporidiu ; While the yeast species implicated in plant disease control activities includes Candida tropicals, Candida valida, Candida saitoana, Saccharomyces cerevisiae, Saccharomyces kudriavzevii, Rhodotorula glutinis, Rhodotorula mucilaginosa, Zygosaccharomyces bailli, Aureobasidium sp, Pichia caribaea, Geotrichum candidum, Trichosporon asahii and Eremothecium cymbalariae. The diverse functionality of these yeasts is discussed in this paper.

Antimicrobial Activity and Metabolite Fingerprinting of a Microcolonial Fungal Isolate TD-082 from the Arid Thar Desert, India

Aims:: This study aimed at bioprospecting underexplored extreme habitats (Thar desert, India) for novel bio- and chemo-diversity. Background:: Bioactive metabolites from microorganisms, such as fungi from underexplored habitats, serve as basic skeletons of therapeutic agents, including antimicrobials, combating the effect of multidrug resistance of pathogens. Objectives:: The main objectives of the current study are (i) characterization of isolate TD-082 and (ii) metabolite fingerprinting of butanol extract showing antimicrobial compounds. Methods:: In search of novel antimicrobial drugs, a promising microcolonial fungus TD-082, obtained from the Thar Desert, India, was identified by ITS1–5.8S–ITS2 sequencing. Phenotypic characteristics were marked by microscopy. The fungus was investigated for antimicrobial activity against a panel of Gram-positive, Gram-negative bacteria and fungi. Butanol extract that showed the best antimicrobial activity was partially purified; fractions exhibiting antimicrobial activity were pooled and fingerprinted by GC-MS analysis. Results:: Sequencing data indicated that the isolate belonged to Aureobasidium sp. It showed 96% similarity to Aureobasidium iranianum and Kabatiella bupleuri, and 95 % to A. thailandense and A. subglaciale. Microscopy results confirmed that it belongs to Aurebasidium sp. Metabolite fingerprinting showed tentatively ten novel compounds belonging to three major categories, hydrocarbons, fatty acids, and peptides. Conclusion:: The study shows that understudied habitats, such as deserts, can provide skeletons for novel compounds from novel microorganisms. The study can be expanded to other niche habitats with higher chances of identifying more novel bioactive compounds.

Comparative biodeterioration at air interfaces of adipate-based polyester polyurethane coatings by fungal microcolonies of Aureobasidium sp. W12

Understanding conditions that enable environmentally common microbes to aggressively deteriorate polymer materials are important for predicting and controlling the environmental fates of these materials. For protective paints and coatings in terrestrial environments, processes at air interfaces are among important factors to understand. Here, we track fungal biodeterioration at air/solid polymer interfaces under nutrient limitation and high humidity, using polymer compositions common in commercial polyester polyurethanes. A fungal isolate, Aureobasidium sp. W12, was collected from an aircraft and identified as a polyester degrader through screening assays. Two polyadipate-based materials were then used for W12 coating deterioration analysis: a commercial polyester polyurethane, Irogran® PS455–203, and a model polyester urethane, PEA-HM. Single and micro-aggregated cell clusters distributed within ∼1.5 mm diameter regions were prepared on the polymer surfaces and incubated with no supplemental nutrients at >95% relative humidity for up to 13 days. Coating deterioration was semi-quantitatively monitored through ester carbonyl loss by transmission FTIR spectroscopy and both materials were rapidly deteriorated, although at different rates. With ∼0.5 monolayer cell surface coverage, PEA-HM showed about 6 × greater molar ester deterioration versus Irogran® over the first 24 h. By 13 days, the polyester fractions of Irogran coatings were deteriorated to an average depth of about 0.1 µm, while PEA-HM coatings about 1 µm thick were completely deteriorated in 5 days within and beyond cell covered regions. Localized analysis of non-uniform PEA-HM deterioration showed that quantities on the order of 10 individual Aureobasidium yeast cells could locally deteriorate through 1–2 µm of PEA-HM coating within 12 days (with deterioration rates up to about 2 × 10−6 µmol ester / (cell × day)). These results correlate conditions and polymer properties that promote high deterioration potentials of Aureobasidium W12 microcolonies at air / coating interfaces.

Antimicrobial volatiles emitted by members of the nest microbiome of social spiders.

Microbes produce and respond to a range of structurally and functionally diverse volatiles. Many microbial volatiles have antimicrobial properties. Since volatiles can diffuse through complex 3D systems like spider nests, they are promising pathogen protection for social arthropods. Here, we analyzed the volatilomes of five nest microbiome members of the Namibian, social spider Stegodyphus dumicola, namely the bacteria Massilia sp. IC2-278, Massilia sp. IC2-477, Sphingomonas sp. IC-11, Streptomyces sp. IC-207, and the fungus Aureobasidium sp. CE_32, and tested their antimicrobial activity against two putative spider pathogens, namely Bacillus thuringiensis and Purpureocillium lilacinum. Most nest microbiome members released volatilomes with antibacterial and/or antifungal activities under in vitro conditions. The analysis of their volatilomes using GC/Q-TOF revealed that they include numerous antimicrobial volatiles. We tested the antimicrobial activity of five pure volatile compounds found in the volatilomes and revealed that all of them were antibacterial and/or antifungal. We could not identify the same antimicrobial volatiles as in a previous in situ study, but our results indicate that social spider-associated microorganisms as a source of antimicrobial volatiles are important for pathogen inhibition. Additionally, we showed the influence of the volatilomes on the antibiotic sensitivity of B. thuringiensis offering novel approaches to counter antibiotic resistance.

Efficient phosphorus removal by a novel halotolerant fungus Aureobasidium sp. MSP8 and the application potential in saline industrial wastewater treatment

Efficient halotolerant phosphorus accumulation microorganisms are of great significance for the treatment of high-salt wastewater. In this study, a halotolerant fungus strain named MSP8 was isolated and identified as Aureobasidium sp. Salinity resistance results showed that strain MSP8 can resist the salinity from 0% to 17%, and 77.2% phosphorus removal was achieved at the optimal salinity of 5%. The strain also showed wide environmental adaptability (pH of 3–7; temperature of 20–30 °C). Batch tests and scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) characterization results verified the key role of extracellular polymeric substance (EPS) secreted by MSP8 in phosphorus removal. The actual brewery and chemical wastewater treatments exhibited that above 53.5% of phosphorus can be removed by MSP8. The excellent adaptation of MSP8 made it a potential candidate for phosphorus removal especially in saline wastewater treatment.

Screening of fungi isolates from soil, pulp waste water and rotten wood for cellulase producing potentials

Pulp waste water, soil from agricultural waste dump site and rotten wood were investigated for the presence of fungi with cellulolysic ability. Fungi Isolates obtained from the samples were identified based on cultural and morphological characteristics. Seven species of fungi namely, Aspergillus niger, Rhizopus oryzea and Fusarium from soil, Penicillium notatum, Mucor resmosus and Aureobasidium sp from rotten wood, Trichoderma citrinoviride, Fusarium salani, A niger and P notatum from pulp waste water were isolated. Among the seven fungi species , A. niger, F. salani, and P. notatum recorded the highest frequency of occurrence, (2), while T. citrinoviride, R. oryzea, Aureobassidium sp recorded frequency occurrence of one (1)each and the cellulytic activity was determined by the ratio of zone of clearing and colony diameter. The difference in zone of clearing produced by the fungi isolates (A. niger, T. citrinoviride, F. salani), on CMC containing plate were not significantly different at (p˂ 0.05). Highest cellulase activity ratio was exhibited by T. citrinoviride (1.39), followed by A. niger from soil (1.30).This result highlights the potential of T citrinoviride as strain for industrial production of cellulolysic enzyme.Keywords: Cellulase, Enzymes, Aspergillus sp., A. niger

Yeasts from Nanfeng mandarin plants: occurrence, diversity and capability to produce indole-3-acetic acid

Plant growth promoters produced by microorganisms can play a significant role in the induction of some important physiological responses in the growth and development of plants. In this study, we provided a first insight into revealing the diversity of cultivable yeasts associated with Nanfeng mandarin (Citrus reticulata cv. Blanco) in China. Their capability to produce indole-3-acetic acid (IAA) was analyzed. A total of 796 yeast strains were obtained by the enrichment isolation technique from citrus soil, citrus leaves, citrus peel and citrus pulp of Nanfeng mandarin samples. On the basis of the 26S rDNA partial sequence analysis, the strains were identified as 14 yeast species in 9 genera belonging to Hanseniaspora sp., Pichia sp., Candida sp., Sporidiobolus sp., Meyerozyma sp., Symmetrospora sp., Rhodotorula sp., Starmerella sp. and Aureobasidium sp. The most abundant species in citrus soil were Starmerella meliponinorum and Meyerozyma caribbica. The species prevailing in citrus peel was Hanseniaspora opuntiae. Citrus pulp was rich in Meyerozyma guilliermondii. Additionally, Aureobasidium pullulans and H. opuntiae were the dominant species in citrus leaves. All yeast species obtained were accessed for the capability to produce IAA: 26 strains in seven species showed the capability of producing IAA. Rhodotorula paludigena produced the highest IAA concentrations of 76.22 mg/L. Our study confirms the phylogenetic diversity of yeast associated with Nanfeng mandarin and highlights that these yeast strains are promising resources of microbial fertilizer.

Cloning, deletion, and overexpression of a glucose oxidase gene in Aureobasidium sp. P6 for Ca2+-gluconic acid overproduction

This study aimed to overexpress a glucose oxidase gene (GOD1) in Aureobasidium sp. P6 to achieve Ca2+-gluconic acid (GA) overproduction. The GOD1 gene was cloned, deleted, and overexpressed. A protein deduced from the GOD1 gene of Aureobasidium sp. P6 strain had 1824 bp that encoded a protein with 606 amino acids, with a conserved NADB-ROSSMAN domain and a GMC-oxred domain. Deleting the GOD1 gene made the disruptant GOK1 completely lose the ability to produce GA and GOD1 activity, whereas overexpressing the GOD1 gene rendered the transformant GOEX8 to produce considerably more Ca2+-GA (160.5 ± 5.6 g/L) and higher GOD1 activity (1438.6 ± 73.2 U/mg of protein) than its parent P6 strain (118.7 ± 4.3 g/L of Ca2+-GA and 1100.0 ± 23.6 U/mg of GOD1 protein). During a 10-L fermentation, the transformant GOEX8 grown in the medium containing 160.0 g/L of glucose produced 186.8 ± 6.0 g/L of Ca2+-GA, the yield was 1.2 g/g of glucose, and the volumetric productivity was 1.7 g/L/h. Most of the produced GOD1 were located in the yeast cell wall. The purified product was identified to be a GA. The transformant GOEX8 overexpressing the GOD1 gene could produce considerably more Ca2+-GA (186.8 ± 6.0 g/L) than its wild-type strain P6.

Immobilization of Fructofuranosidase from Aureobasidium sp. Onto TiO2 and Its Encapsulation on Gellan Gum for FOS Production

AbstractFructofuranosidase (EC 3.2.1.26) fromAureobasidiumsp. ATCC 20524, recovered from 5 L fermented medium, purified by two simple steps with a yield of 65 % and a purification factor of 16, was immobilized by adsorption onto titanium dioxide (FTIO). The enzyme was also covalently immobilized onto TiO2coated with polyethyleneimine (FTIOP) and encapsulated in gellan gum (FTIOPG). FTIO and FTIOP recorded an activity of 903 U g−1and 9212 U g−1, respectively. The immobilized enzyme showed high activity and stability at pH levels ranging from 4.0 to 8.0 and there were no changes in the temperature profile for either methodology when compared with free fructofuranosidase. The immobilized biocatalysts were reused 7 times for FOS production without significant activity loss, except FTIO at pH 5.0. Gellan gum was used for FTIOP encapsulation. FOS production was performed in a batch and a continuous reactor using FTIOPG as a biocatalyst. Batch conversion (gFOS/ginitial sucrose) was around 60 % for initial sucrose concentrations of 100, 300 and 600 g L−1, at a time of maximum conversion. Fixed-bed reactor operational stability was remarkable, providing a constant FOS production in the outlet of the column during 720 h.

Overexpression of a pyruvate carboxylase gene enhances extracellular liamocin and intracellular lipid biosynthesis by Aureobasidium melanogenum M39

Abstract The pyruvate carboxylase-encoding PYC1 gene from the yeast strain Aureobasidium sp. P6, which is a polymalate over-producer, was actively overexpressed in the marine-derived yeast Aureobasidium melanogenum 9-1, which is a heavy oil (liamocin) producer. The resulting PYC1-over-expressing transformant M39 produced 35.3 ± 1.2 g/l liamocins and 24.6 ± 0.5% (w/w) intracellular oil, and its cell dry weight was 17.0 ± 1.6 g/l. On the other hand, wild-type strain 9-1 only produced 27.4 ± 0.3 g/l liamocins and 22.6 ± 0.8% (w/w) intracellular oil and had a cell dry weight of 15.3 ± 2.0 g/l within 168 h. The results suggested that the over-expression of the PYC1 gene enhanced the biosynthesis of liamocins and intracellular lipids in transformant M39 due to the enhanced biosynthesis of citric acid, which could be the precursor for the biosynthesis of the intracellular lipids and extracellular liamocins. During fermentation, 43.04 ± 1.2 g/l of extracellular liamocins, 17.7 ± 0.5 g/l of cell dry weight and 23.8 ± 0.2 g/l of intracellular lipids were produced by transformant M39 within 156 h, leaving 2.1% reducing sugar in the fermented medium. Moreover, the strong alkaline hydrolysis products of the extracellular liamocins mainly contained 5-hydroxy-2-decenoic acid lactone (92.1 ± 0.3%), hexadecanoic acids (C16:0, 3.3 ± 0.04%), octadecadienoic acids (C18:2, 1.0 ± 0.2%) and octadecanoic acids (C18:0, 3.6 ± 0.01%), while the intracellular lipids mainly contained C16:0, C16:1, C18:0, C18:1 and C18:2 fatty acids.

Comparative efficacy of locally isolated fungal strains for Pb(II) removal and recovery from water

The present investigation aimed to study and compare the efficiency of non-viable fungal isolates to remove divalent lead (Pb(II)) from aqueous streams. The selected fungal isolates showed identity with Aspergillus caespitosus, Aureobasidium sp. RBSS-303 and Aspergillus flavus HF5 as confirmed using gene sequencing of ITS regions of the ribosomal DNA (rDNA). The obtained equilibrium data for Pb(II) biosorption of A. caespitosus fitted better to Langmuir isotherm with maximum sorption capacity of 351.0 mg/g and A. sp. RBSS-303 and A. flavus HF5 showed good fit to Freundlich isotherm with maximum sorption capacity of 271.5 and 346.3 mg/g respectively. The values of thermodynamic factors ascertained the nature of adsorption process is endothermic with A. caespitosus and A. flavus HF5 but exothermic with A. sp. RBSS-303. The experimental data for Pb(II) biosorption fits very well to pseudo second order kinetic model. With HCl the maximum 85.5, 75.3, 73.7% recovery of Pb(II) was obtained from A. caespitosus, A. sp. RBSS-303 and A. flavus HF5, respectively. The observed percentage loss in sorption capacity of Pb(II) was 3.9% by A. flavus HF5, 12.2% by A. caespitosus and 26.6% by A. sp. RBSS-303 after five cyclic studies of sorption and desorption. Results from the study confirmed the efficiency order of A. caespitosus > A. flavus HF5 > A. sp. RBSS-303 to remove and recover Pb(II) from aqueous solution. Finally, the fungal biosorbents can be used as soil conditioning agent after compositing into valuables fungal protein.

Biotransformation of (+)-carvone and (−)-carvone using human skin fungi: A green method of obtaining fragrances and flavours

The synthesis of optically pure compounds is increasingly in demand among the pharmaceutical, fine chemical and agro-food industries, while the importance of chirality in the activity and biological properties of many compounds has previously been established. The aim of the present study was therefore to evaluate the biotransformation capacities of (+)-carvone and (−)-carvone using the fungi Scolecobasidium sp, three lines of Cladosporium sp, Phoma sp, Aureobasidium sp and Epicoccum sp, all obtained from human skin. The seven fungi evaluated were capable of hydrogenating the activated alkene, followed by the reduction of ketone to chiral alcohol, with conversions between 9.5 and 100%, and with diastereomer excess (d.e.) of over 89% of dihydrocarveol when (+)-carvone was used as a substrate. These results demonstrate that the filamentous fungi of human skin are potential biocatalytic tools for obtaining chiral alcohols.

ISOLASI DAN KARAKTERISASI JAMUR LIGNINOLITIK SERTA PERBANDINGAN KEMAMPUANNYA DALAM BIODELIGNIFIKASI

Fungi can survive in various environments on different media including wood. Lignin in timber is hard to degrade efficiently because of its polymer form, and only a few of it can be hydrolyzed because of its composite and complex structure. Ligninolytic fungi produce an extracellular enzyme to withstand to toxic or mutagenic chemicals exposure and known to degrade different types of pollutant compounds. Lignin decomposers were also known to play a significant role in the pulping process of paper mills, used in waste treatment such as textile and hydrocarbon wastes. This study was conducted to obtain fungal isolates that have de-lignification capability and to compare the ability of fungal isolates to degrade lignin. The research isolated samples from rotten wood and soil using selective lignin medium with tannic acid as sole C source. This study characterized the isolates by its morphology and identified using the Morphology and Taxonomy of Fungi book by Bessey (1950) as a reference. This study compared the ligninolytic capability by measuring the transparent zone formed on selective lignin media. This research found 14 isolates of fungi and all of them had a ligninolytic capability. Aspergillus niger isolate has the highest ligninolytic capability by producing 6.45 cm clear zone diameter on the 7th day. Aureobasidium sp has the smallest clear zone diameter of 1.9 cm within the same period.

A novel strain of Aureobasidium sp. TeO12 for theophylline production from caffeine.

A total of 40 fungal cultures were isolated for their ability to grow on caffeine as a sole source carbon and nitrogen, and further screened for theophylline-producing activities under the growing cell system. Based on thin-layer chromatography and high-performance liquid chromatography analyses, the potent strain Aureobasidium sp. TeO12 was chosen for its capability to generate theophylline via biotransformation of caffeine. It was identified based on phenotypic characteristics and its ITS1-5.8S-ITS2 rDNA sequencing data (GenBank accession number no. KT439072). To improve theophylline yield, the effects of various factors, such as resting cell density, Fe(II) concentration, and course of the transformation of caffeine, were studied in a biotransformation reaction containing 0.1M sodium phosphate buffer (pH 7), Aureobasidium sp. TeO12 resting cells as the whole-cell catalyst and caffeine (2.5g/L) as the substrate, and the reaction was incubated at 30°C on an orbital shaker (200rpm). The results indicated that optimal combination included resting cell density 6g/L, Fe(II) concentration 75mg/L, and the biotransformation time 72h. Under these optimal reaction conditions, the highest theophylline concentration of 1.55g/L (molar yield of 67%) with an average degradation yield of the substrate of about 83% was obtained in the biotransformation process. This is the first report on the biotransformation of caffeine into theophylline by a novel strain of the genus Aureobasidium.

Endophytic Fungi from Frankincense Tree Improves Host Growth and Produces Extracellular Enzymes and Indole Acetic Acid.

Boswellia sacra, an economically important frankincense-producing tree found in the desert woodlands of Oman, is least known for its endophytic fungal diversity and the potential of these fungi to produce extracellular enzymes and auxins. We isolated various fungal endophytes belonging to Eurotiales (11.8%), Chaetomiaceae (17.6%), Incertae sadis (29.5%), Aureobasidiaceae (17.6%), Nectriaceae (5.9%) and Sporomiaceae (17.6%) from the phylloplane (leaf) and caulosphere (stem) of the tree. Endophytes were identified using genomic DNA extraction, PCR amplification and sequencing the internal transcribed spacer regions, whereas a detailed phylogenetic analysis of the same gene fragment was made with homologous sequences. The endophytic colonization rate was significantly higher in the leaf (5.33%) than the stem (0.262%). The Shannon-Weiner diversity index was H′ 0.8729, while Simpson index was higher in the leaf (0.583) than in the stem (0.416). Regarding the endophytic fungi’s potential for extracellular enzyme production, fluorogenic 4-methylumbelliferone standards and substrates were used to determine the presence of cellulases, phosphatases and glucosidases in the pure culture. Among fungal strains, Penicillum citrinum BSL17 showed significantly higher amounts of glucosidases (62.15±1.8 μM-1min-1mL) and cellulases (62.11±1.6 μM-1min-1mL), whereas Preussia sp. BSL10 showed significantly higher secretion of glucosidases (69.4±0.79 μM-1min-1mL) and phosphatases (3.46±0.31μM-1min-1mL) compared to other strains. Aureobasidium sp. BSS6 and Preussia sp. BSL10 showed significantly higher potential for indole acetic acid production (tryptophan-dependent and independent pathways). Preussia sp. BSL10 was applied to the host B. sacra tree saplings, which exhibited significant improvements in plant growth parameters and accumulation of photosynthetic pigments. The current study concluded that endophytic microbial resources producing extracellular enzymes and auxin could establish a unique niche for ecological adaptation during symbiosis with the host Frankincense tree.

Production, Purification, and Gene Cloning of a β-Fructofuranosidase with a High Inulin-hydrolyzing Activity Produced by a Novel Yeast Aureobasidium sp. P6 Isolated from a Mangrove Ecosystem.

After screening of over 300 yeast strains isolated from the mangrove ecosystems, it was found that Aureobasidium sp. P6 strain had the highest inulin-hydrolyzing activity. Under the optimal conditions, this yeast strain produced an inulin-hydrolyzing activity of 30.98 ± 0.8U/ml after 108h of a 10-l fermentation. After the purification, a molecular weight of the enzyme which had the inulin-hydrolyzing activity was estimated to be 47.6kDa, and the purified enzyme could actively hydrolyze both sucrose and inulin and exhibit a transfructosylating activity at 30.0% sucrose, converting sucrose into fructooligosaccharides (FOS), indicating that the purified enzyme was a β-D-fructofuranosidase. After the full length of a β-D-fructofuranosidase gene (accession number KU308553) was cloned from Aureobasidium sp. P6 strain, a protein deduced from the cloned gene contained the conserved sequences MNDPNGL, RDP, ECP, FS, and Q of a glycosidehydrolase GH32 family, respectively, but did not contain a conserved sequence SVEVF, and the amino acid sequence of the protein from Aureobasidium sp. P6 strain had a high similarity to that of the β-fructofuranosidase from any other fungal strains. After deletion of the β-D-fructofuranosidase gene, the disruptant still had low inulin hydrolyzing and invertase activities and a trace amount of the transfructosylating activity, indicating that the gene encoding an inulinase may exist in the Aureobasidium sp. P6 strain.

Removal and recovery of lead (Pb2+) from industrial effluent using indigenous and tailor-made Aureobasidium sp. RBSS-303.

The objective of this study was to assess the removal and recovery of Pb-II from industrial wastewater using a locally isolated strain of Aureobasidium sp. RBSS-303. The initial Pb2+ concentration of 600 mg/L resulted in maximum uptake capacity (Qmax 235.1±0.3 mg/g). The biosorbent revival was attained by contacting with HCl (0.01 M), with 75.3% recovery of Pb2+. The Freundlich isotherm best explains the Pb2+ sorption performances. Maximum adsorption distribution coefficient of 1,309.6 mg metal/mL was observed at initial Pb2+ concentration value of 100 mg/L. Evaluation of nine kinetic models showed the removal rate of Pb2+ was reliant on diffusion control pseudo-second-order and saturation-mixed-order kinetic models with a high correlation coefficient value (R=0.99). Fourier transform infrared spectroscopy analysis showed the major contribution of -NH2 and -CN ligands of Aureobasidium sp. RBSS-303 in the sorption phenomenon of Pb2+. The biosorption assays carried out with effluent of the paint industry showed 76.8% efficiency for Pb2+ removal by the candidate biosorbent, regardless of the complex composition of the industrial effluent.