Anaerobic bacterial responses to carbonaceous materials and implications for contaminant transformation: Cellular, metabolic, and community level findings.

Carbonaceous materials (CM) enhance the abundance and activity of bacteria capable of persistent organic (micro)pollutant (POP) degradation. This review synthesizes anaerobic bacterial responses to minimally modified CM in non-fuel cell bioremediation applications at three stages: attachment, metabolism, and biofilm genetic composition. Established relationships between biological behavior and CM surface properties are identified, but temporal relationships are not well understood, making it difficult to connect substratum properties and "pioneer" bacteria with mature microorganism-CM systems. Stark differences in laboratory methodology at each temporal stage results in observational, but not causative, linkages as system complexity increases. This review is the first to critically examine relationships between material and cellular properties with respect to time. The work highlights critical knowledge gaps that must be addressed to accurately predict microorganism-CM behavior and to tailor CM properties for optimized microbial activity, critical frontiers in establishing this approach as an effective bioremediation strategy.

Morphological and molecular characterization of coprinoid fungi newly recorded for the mycobiota of Iran.

Twenty-five specimens of coprinoid fungi were collected during an ongoing survey of agaric fungi in Kermanshah Province, western Iran. The specimens were identified based on morphological characteristics and molecular analysis of internal transcribed spacer sequences. Five species of Coprinellus viz C. disseminates, C. flocculosus, C. micaceus, C. radians and C. xanthothrix, three species of Coprinopsis viz C. atramentaria, C. insignis and C. semitalis and two species of Coprinus viz C. pinetorum and C. sterquilinus were identified. Among the species identified in this research, three unreported species from Iran namely C. insignis, C. semitalis and C. pinetorum are reported. Detailed morphological descriptions and illustrations of this three newly-recorded species were provided here and their evolutionary relationships were presented by the constructing of a phylogenetic tree.

Antimicrobial effect of the Lingzhi or Reishi medicinal mushroom, Ganoderma lucidum (higher Basidiomycetes) and its main compounds.

Mushrooms are considered one of the richest sources of natural antibiotics, and various species of them inhibit the growth of a wide diversity of microorganisms. Ganoderma lucidum, a well-known medicinal mushroom. has many pharmacological and biological activities including an antimicrobial effect, although few studies have investigated the antibacterial and antifungal effects of its purified compounds. The chemical structure of the purified compounds from the hexane fraction was elucidated as ergosta-7,22-dien-3ß-yl acetate, ergosta-5,7,22-trien-3ß-yl acetate (isopyrocalciferol acetate), ergosta-7,22-dien-3-one, ergosta-7,22-dien-3ß-ol, and ergosta-5,7,22-trien-3ß-ol (ergostrol). In addition, the structure of ganodermadiol was demonstrated after purification from the chloroform fraction. The fractions inhibited Gram-positive bacteria and yeast, with minimum inhibitory concentration values of 6.25 mg/mL, but were ineffective against Gram-negative bacteria in the tested concentrations. The results were comparable for isolated compounds, whereas the mixture of ergosta-7,22-dien-3ß-yl acetate and isopyrocalciferol acetate was weakly effective against Escherichia coli (minimum inhibitory concentration, 10 mg/mL). It could be assumed that the antimicrobial effect of crude fractions is the consequence of mixing triterpenoid and steroid compounds.

Chemotherapeutic/chemopreventive role of retinoids in chemically induced skin carcinogenesis in albino mice.

OBJECTIVE: To determine the chemotherapeutic effect of retinoids on albino mouse skin. METHODS: Eighty albino mice were selected for this study and were divided into four groups (A-D, 20 mice in each group). 7,12-Dimethylbenz(a)anthracene (DMBA) and tetradecanoylphorbal-13-acetate (TPA) were given for 15 weeks to produce tumors. Retinoids were given topically and orally after the development of tumors for the following 15 weeks. RESULTS: Of the 80 mice, 69 (86.25%) developed different types of lesion and 11 (13.75%) remained lesion free. Of the 69 mice that developed lesions, 50 (62.50%) developed benign lesions and 19 (23.75%) developed malignant lesions. In all groups of mice, treatment with retinoids was effective against all benign lesions and the early stages of carcinogenesis of the skin. The chemotherapeutic effect against malignant tumors was not satisfactory. CONCLUSION: This study demonstrates that retinoids are effective as chemopreventive agents in premalignant lesions of the skin, but have a very weak chemotherapeutic role in malignant neoplasms. If retinoids are given at an early stage, they can cause regression of premalignant lesions of the skin. They are best administered both orally and parenterally. These agents should be recommended as they reduce the potential effects of carcinogenesis.