Galactomannans for Entrapment of Gliomastix murorum Laccase and Their Use in Reactive Blue 2 Decolorization

In the present study, a novel laccase from ascomycete Gliomastix murorum was produced in agro-industrial wastes and entrapped in galactomannan beads for Reactive Blue 2 (Rb-2) decolorization. The maximum laccase production in agave bagasse-based medium occurred at 72 h (1798.6 UL−1). Entrapped laccase decolorized ˃80% of 0.5 mM Rb-2 in 2 h without the addition of redox mediator. Km for Rb-2 substrate was 1.42 mM, with a Vmax of 1.19 µmol min−1 for entrapped laccase. Galactomannan matrices produce stability to acid pH (2–5) and temperatures from 20–70 °C. Reusability assays showed that entrapped laccase could retain efficient Rb-2 decolorization of ˃80% six times. In general, galactomannan used for entrapment of laccase provides economic advantages in large-scale wastewater treatment due to its natural origin and efficient results.

Chemical Composition and in Vitro Antimicrobial Activity of the Volatile Oils from Gliomastix murorum and Pichia guilliermondii, Two Endophytic Fungi in Paris polyphylla var. yunnanensis

Volatile oils were obtained by hydrodistillation from Gliomastix murorum and Pichia guilliermondii, two endophytic fungi isolated from the traditional Chinese medicinal herb Paris polyphylla var. yunnanensis. The oils were analyzed for their chemical composition by gas chromatography-mass spectrometry (GC-MS). Palmitic acid (15.5%), (E)-9-octadecenoic acid (11.6%), 6-pentyl-5,6-dihydropyran-2-one (9.7%), and (7Z,10Z)-7,10- hexadecadienoic acid (8.3%) were the major compounds of the 40 identified components in G. murorum volatile oil. 1,1,3a,7-Tetramethyl-1a,2,3,3a,4,5,6,7b-octahydro-1H-cyclopropa[a]- naphthalene (25.9%), palmitic acid (15.5%), 1-methyl-2,4-di- (prop-1-en-2-yl)-1- vinylcyclohexane (7.9%), (E)-9-octadecenoic acid (7.3%), and (9E,12E)-ethyl-9,12-octadecadienoate (5.2%) were the major compounds of the 27 identified components in P. guilliermondii volatile oil. The in vitro antimicrobial activity of the volatile oils was also investigated to evaluate their efficacy against six bacteria and one phytopathogenic fungus. The minimum inhibitory concentration (MIC) values of the volatile oils against the test bacteria ranged from 0.20 mg/mL to 1.50 mg/mL. One of the most sensitive bacteria was Xanthomonas vesicatoria with an MIC of 0.20 mg/mL and 0.40 mg/mL for G. murorum and P. guilliermondii, respectively. The mean inhibitory concentration (IC50) of the volatile oils against spore germination of Magnaporthe oryzae was 0.84 mg/mL for G. murorum and 1.56 mg/mL for P. guilliermondii. These results indicated that the volatile oils from the endophytic fungi have strong antimicrobial activity and could be a potential source of antimicrobial ingredients.

Seasonality of forest soil microfungi in southern Quebec

Data on microfungi isolated from the soils of four forests in southern Quebec were analysed, to detect seasonal changes in the community. Two-way analysis of variance showed that significant changes occurred for individual species, both between sites and sample times, and that significant season–site interactions occurred. Discriminant analysis showed that at all sites, there was a tendency for the community to shift towards a characteristic winter community during the colder periods of the year. Geomyces pannorus, Paecilomyces fumosoroseus, Pae. marquandii, Penicillium purpurogenum, Trichoderma koningii, T. polysporum, Botryotrichum piluliferum, Chrysosporum verrucosum, and Exophiala sp. LP111 were associated with samples from the colder months, in one or more of the sites. Sterile fungi, Fusarium solani, T. harzianum, T. hamatum, Pen. thomii, and Staphyotrichum coccosporum tended to be associated with the warmer months. There was also a tendency for samples from the seasonal "extremes" (warm dry summer samples and cold winter samples) to show some similarities. It is suggested that this trend may exist because fungi abundant during relatively unfavorable times of the year are not good competitors and therefore should be considered as "survivors." In this study, Exophiala sp. LP111, Gliomastix murorum, Paecilomyces carneus, T. viride, and Trichoderma sp. LP58 may fall into this category.