Degradation of the main components of cellulose-paint thinner by the mould Scopulariopsis brevicaulis cultured on rice hulls

AIMS: Biodegradation of the main components of the cellulose-paint thinner (toluene, acetone, isopropanol and xylenes) by Scopulariopsis brevicaulis, isolated from a thinner biodegradation microbial consortium was investigated. METHODS AND RESULTS: Our results showed that 90% of S. brevicaulis conidia survived after 4 weeks in a cellulose-paint thinner saturated atmosphere. The mould was able to grow under these environmental conditions with a low development of conidia. The biodegradation potential of S. brevicaulis was established with and without support material (rice hulls). Biodegradation without support was very limited, <10% for all the components quantified. There was notable thinner biodegradation when the fungus was grown on rice hulls. CONCLUSIONS: Our results suggest the potential use of fungi in biofiltration systems employed in biodegradation of the main components of the cellulose-paint thinner. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of volatile organic compounds biodegradation by this fungal species.     

Detoxification of Jatropha curcas Seed Cake by Scopulariopsis brevicaulis Fermentation

膏桐饼作为生物柴油产业中产生的最大宗副产物,其高蛋白、低纤维含量的特性有望使其开发成为一种优良的蛋白饲料,但毒性限制了其直接作为饲料利用.发酵是多种饼粕脱毒的常用方法.分离、纯化膏桐根际微生物并分别发酵膏桐饼,用甲醇提取发酵膏桐饼的毒性成分并溶于水中,通过鲤鱼存活时间来评价不同菌株发酵膏桐饼的毒性,筛选获得了一株能够在膏桐饼上快速生长并能有效脱除膏桐饼毒性的短帚霉.脱毒小桐子饼组的小鲤鱼存活时间与对照组相比延长了1.22倍.     

Purification and partial characterization of two extracellular keratinases of Scopulariopsis brevicaulis

Two extracellular keratinases of Scopulariopsis brevicaulis were purified and partially characterized. The enzymes were isolated by the techniques of gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). These keratinases (K I & K II) were purified approximately 33 and 29 fold, respectively. SDS-PAGE of the products of gel filtration chromatography (K I & II) produced only one band each, suggesting homogeneity. The optimum pH for both keratinases was 7.8, while the optimum temperatures were 40°C (K I) and 35°C (K II). Estimated molecular weights were 40–45 KDa and 24–29 KDa for K I & K II respectively. Both keratinases were inhibited by phenylmethylsulfonyl fluoride which suggests a serine residue at or near an active site.     

Optimization of extracellular keratinase production by poultry farm isolate Scopulariopsis brevicaulis

A Scopulariopsis brevicaulis poultry farm isolate was chosen to study factors influencing keratinase production. The parameters were optimized by factorial design. The highest enzyme production by this fungus was obtained at pH 7.5, a temperature of 30 degrees C and a growth period of 5 weeks. The production of the enzyme was enhanced when the culture medium was supplemented with glucose (1%), sodium nitrate (2%), feather (1.5%) and CaCl(2) (1 mM). According to the responses from the experimental design, the effects of each variable were calculated, and the interactions between them were determined. The experimental values were found to be in accordance with the predicted values, the correlation coefficient is 0.9978.     

Effect of keratin on the lipid composition of Scopulariopsis brevicaulis (Bainier)

Lipid content and composition of Scopulariopsis brevicaulis cultured with or without its natural substrate keratin was investigated. Lipid content was found to be lower in the presence of keratin (maximum 12% against 19% in the absence of keratin), with differences in levels of linoleic acid (C₁₈₌₂), palmitic (C₆₀) and to a lesser extent palmitoleic (C₁₆₌₁) and -linolenic (C₁₈₌₃) acids. The degree of unsaturation was correspondingly lower in the organisms cultured with keratin as substrate.     

建立真菌透甲模型及红色毛癣菌和短帚霉透甲时间的比较

目的通过建立真菌透甲模型,观察真菌透甲时间,来探讨红色毛癣菌与短帚霉的相互作用。方法建立真菌透甲模型,分为红色毛癣菌组、短帚霉组、短帚霉-红色毛癣菌混合组,分析各组透甲时间。结果透甲模型中,红色毛癣菌的透甲时间为（9.46±1.89）d,短帚霉的透甲时间为（2.62±0.96）d,混合组中短帚霉的透甲时间为（2.54±0.78）d。结论体外透甲模型中,短帚霉比红色毛癣菌先穿透甲板。混合组中,红色毛癣菌对短帚霉的透甲时间无明显影响。     

Secretion of keratinolytic enzymes and keratinolysis by Scopulariopsis brevicaulis and Trichophyton mentagrophytes: regression analysis

A survey on keratinophilic fungi from poultry-farm soils at Namakkal and from feather dumping soils at Chennai, India, revealed the existence of 34 species of fungi. Most of the fungi exhibited variable efficiency in producing extracellular keratinase when grown in plates with chicken feathers as the sole carbon and nitrogen source. The fungi Aspergillus flavus, Aspergillus niger, Aspergillus versicolor, Chrysosporium state of Arthroderma tuberculatum, Paecilomyces carneus, Scopulariopsis brevicaulis, Trichoderma viride, and Trichophyton mentagrophytes were efficient candidates to degrade the feathers. However, when cultivating the strains in submerged conditions in a medium containing chicken feathers as the sole nutrients source, Aspergillus glaucus, Chrysosporium keratinophilum, Curvularia lunata, Fusarium solani, and Penicillium citrinum also proved to be potent. Among all species, S. brevicaulis and Trichophyton mentagrophytes produced higher amounts of keratinase in both methods. Conditions for keratinase production were optimized by statistical design and surface plots. The highest keratinase activity was estimated by S. brevicaulis (3.2 KU/mL) and Trichophyton mentagrophytes (2.7 KU/mL) in the culture medium with chicken feathers and shows (79% and 72.2% of degrading ability, respectively).     

In vitro antifungal activity of voriconazole against dermatophytes and superficial isolates of Scopulariopsis brevicaulis

We have studied the in vitro antifungal activity of voriconazole, fluconazole and itraconazole against 252 clinical isolates of dermatophytes and Scopulariopsis brevicaulis by a standardized agar diffusion method (NeoSensitabs). Several important factors such as temperature (28 degrees C vs. 35 degrees C) and incubation time (2-10 days vs. 18-74 h) were adapted to dermatophytes and Scopulariopsis requirements. Voriconazole showed an excellent activity against most species of dermatophytes, higher than itraconazole and fluconazole. However, S. brevicaulis isolates were highly resistant to all azoles used in this study. Voriconazole might be an interesting antifungal alternative to refractory superficial mycoses.     

Control of Dimorphism in Mucor by Hexoses: Inhibition of Hyphal Morphogenesis

In anaerobic cultures of Mucor rouxii, morphogenesis was strongly dependent on hexose concentration as well as pCO(2). At low levels of hexose or CO(2), or both, hyphal development occurred; at high levels, the fungus developed as yeast cells. Other dimorphic strains of Mucor responded similarly to hexose and CO(2) but differred in their relative sensitivity to these agents. Glucose was the most effective hexose in eliciting yeast development of M. rouxii; fructose and mannose were next; and galactose was last. The fungus may be grown into shapes covering its entire dimorphic spectrum simply by manipulating the hexose concentration of the medium. Thus, at 0.01% glucose, hyphae were exceedingly long and narrow; at higher sugar concentrations, the hyphae became progressively shorter and wider; finally, at about 8% glucose, almost all cells and their progeny were isodiametric (spherical budding cells). Such yeast development occurred without a manifested requirement for exogenous CO(2). The stimulation of yeast development by hexose is not an artifact due to increased production of metabolic CO(2) (hyphae or yeast cells released metabolic CO(2) at similar rates). Presumably, the effect was caused by some other hexose catabolite which interfered with hyphal morphogenesis (apical growth); deprived of its polarity, the fungus grew into spherical yeastlike shapes. Although 10% glucose inhibited the development of hyphae from germinating spores, it did not prevent the elongation of preformed hyphae. This suggests that hexose inhibits hyphal morphogenesis not by blocking the operation of the enzyme complex responsible for apical growth but by preventing its initiation; such inhibition may be regarded as a repression of hyphal morphogenesis.     

On the Mode of Action of Scopulariopsis brevicaulis Proteinase (Prot. II) on the Oxidized Insulin

The proteinase (Prot. II) from Scopulariopsis brevicaulis has rather a broader specificity in its action on oxidized A- and B-chain of bovine insulin, than that of trypsin or chymotrypsin.

The cleavage in the above peptides occurred rapidly at such bonds, where leucine, valine or glutamic acid is linked by its respective carboxyl group, and slowly at the carboxyl side of cysteic acid or alanine.     

Growth and morphogenesis of hyphae from Scopulariopsis brevicaulis (Bainier) in the presence or absence of keratin

Scopulariopsis brevicaulis, Deuteromycete, Hyphomycete is a mainly saprophytic fungus but can grow parasitically on keratin-containing substrates.Growth and morphology of hyphae grown on a semi-synthetic keratin-supplemented medium were compared with those grown on a synthetic medium.Dry weight was lower in the keratin-containing medium and some ultrastructural changes were observed. Hyphae diameter and cell wall thickness were both reduced, and the cultures were seen to colonize the cellophane support. These observations may be related to a physiological requirement of this organism when grown on its natural substrate.     

Keratinolytic activity of purified alkaline keratinase produced by Scopulariopsis brevicaulis (Sacc.) and its amino acids profile

Sodium dodecyl sulfate–polyacrlyamide gel electrophoresis (SDS–PAGE) was used to assess the purity and molecular weight of the previously purified alkaline keratinase enzyme of Scopulariopsis brevicaulis. The enzyme was homogenous, as seen by a single band of protein, and had an apparent molecular weight of 28.5 kDa. Amino acid profile of the purified keratinase revealed that it was composed of 14 different amino acids with high proportions of glutamic acid (20.86%), alanine (14.52%), glycine (14.21%), leucine (8.59%) and serine (7.81%). The enzyme contained moderate amounts of valine (6.01%), threonine (5.58%) and phenyl alanine (5.22%). The purified enzyme of S. brevicaulis exerted a potent keratinolytic activity and was capable to hydrolyze different keratinaceous materials with highest activity on chicken feathers followed by human nails and human hair.     

Dimorphism in Candida albicans: contribution of mannoproteins to the architecture of yeast and mycelial cell walls

Wall mannoproteins of the two (yeast and mycelial) cellular forms of Candida albicans were solubilized by different agents. Boiling in 2% (w/v) SDS was the best method, as more than 70% of the total mannoprotein was extracted. Over 40 different bands (from 15 to 80 kDal) were detected on SDS-polyacrylamide gel electrophoresis of this material. The residual wall mannoproteins were released after enzymic (Zymolyase and endogenous wall beta-glucanases) degradation of wall glucan, suggesting that they are covalently linked to this structural polymer. Four bands (of 160 kDal, 205 kDal and higher molecular mass) were observed in the material released from yeast walls but only the two smaller components were detected in the material obtained from mycelial walls. Moreover, the mannoproteins of high molecular mass, which are covalently linked in walls of normal cells, were not incorporated into walls of regenerating protoplasts, but non-covalently linked mannoproteins were retained from the beginning of the process.     

Morphogenesis and dynamics of the yeast Golgi apparatus

A kinetic and morphometric study was conducted with the electron microscope to clarify the biogenesis and structural diversity of the Golgi apparatus in the yeast Saccharomyces cerevisiae . Secretion was synchronized by inhibiting protein synthesis and/or by subjecting thermosensitive secretory mutants to double temperature shifts. Five membrane-bounded structures disappeared or reappeared in an orderly manner at approximately the rate of secretory protein flow. 1) The first detectable post-ER intermediates were very short-lived clusters of small vesicles that appeared next to the endoplasmic reticulum (ER). 2) Their constituent small vesicles were rapidly bridged by membrane tubules in a SEC18 -dependent manner, giving short-lived tubular clusters of small vesicles, analogous to mammalian vesicular-tubular clusters. 3) Fine and 4) large nodular networks (coated with the Golgi protein Sec7), and 5) secretory granules. Upon relieving a secretory block, each structure successively reappeared, seemingly by transformation of the previous one. When no secretory cargo was to be transported, these structures were not renewed. They disappeared more than five times faster than some Golgi enzymes such as Och1p, implying that the latter are recycled and perhaps partially retained. Retention could arise from intra-compartmental flow of cargo/carrier, hinted at by the varying calibers within a single nodular network.     

Cloning and Sequencing of an Endoglucanase Gene from Scopulariopsis brevicaulis TOF-1212, and Its Expression in Saccharomyces cerevisiae

The egI gene, encoding a major endoglucanase (EGI) of Scopulariopsis brevicaulis TOF-1212, was cloned and sequenced. The egI gene consisted of 868 bp with one intron and encoded a protein of 229 amino acids with a calculated molecular mass of 22,392 daltons. The EGI was assigned to a family 45 of glycosyl hydrolases and showed high similarity with other fungal endoglucanases, especially with those of Humicola grisea and Fusarium oxysporum, on the basis of hydrophobic cluster analysis. The egI gene was expressed under the promoter of the phosphoglycerate kinase gene (PGK) in Saccharomyces cerevisiae. The transformed cells were able to secrete the enzyme efficiently in an active form.