Streptomyces sennicomposti sp. nov., an actinomycete isolated from compost of Senna siamea (Lam.).

A member of the genus Streptomyces, designated RCPT1-4T, was isolated from compost of Senna siamea (Lam.), collected from an agricultural area in Rayong province, Thailand. The spore morphology and the presence of ll-diaminopimelic acid in the peptidoglycan indicate that RCPT1-4T shows the typical properties of members of the genus Streptomyces. On the basis of the results of 16S rRNA gene sequence analysis, the strain should be classified as representing a member of the genus Streptomyces and was most closely related to Streptomyces fumigatiscleroticus NBRC 12999T with the highest 16S rRNA gene sequence similarity of 99.2 %, followed by Streptomyces spiralis NBRC 14215T (99.0 %). In addition, RCPT1-4T shared the highest average nucleotide identity by blast (ANIb) (86.0 %), and digital DNA-DNA hybridization (dDDH) (32.1 %) values with S. spiralis NBRC 14215T. Furthermore, several physiological and biochemical differences were observed between RCPT1-4T and the closely related type strains of species with validly published names. These taxonomic data indicated that RCPT1-4T could be considered to represent a novel species of the genus Streptomyces and the name Streptomyces sennicomposti sp. nov. is proposed for this strain. The type strain is RCPT1-4T (=TBRC 11260T=NBRC 114303T).

Streptomyces musisoli sp. nov., an actinomycete isolated from soil.

An actinobacterium, strain CH5-8T, which formed spiral chains of spore arising from the aerial mycelium, was isolated from rhizosphere soil of Musa spp. The organism exhibited vivid greenish yellow substrate mycelium and easily produced the medium grey aerial spore mass on ISP2 medium. The typical chemotaxonomic properties of members of the genus Streptomyces were observed for strain CH5-8T, e.g. ll-diaminopimelic acid in cell peptidoglycan, MK-9(H8), MK-9(H6), and MK-9(H4) as major menaquinones and anteiso-C15 : 0, iso-C16 : 0, and anteiso-C17 : 0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside were detected in the cells. A combination of morphological and chemotaxonomic data supported the assignment to the genus Streptomyces. The analysis result obtained for the 16S rRNA gene sequence confirmed the taxonomic affiliation at the genus level of this strain. The novel strain CH5-8T showed the highest 16S rRNA gene sequence values to Streptomyces echinatus NBRC 12763T (98.9 %), followed by Streptomyces actinomycinicus RCU-197T (98.9 %). The average nucleotide identity by blast (ANIb) and digital DNA-DNA hybridization values between CH5-8T and its closest relatives, S. echinatus CECT 3313T and S. actinomycinicus RCU-197T, were ≤91.6 % and ≤47.4 %, respectively. The digital DNA G+C content of genomic DNA was 72.1 mol%. On the basis of these phenotypic and genotypic data, strain CH5-8T represents a novel species, for which the name Streptomyces musisoli sp. nov. is proposed. The type strain is CH5-8T (=TBRC 9950T=NBRC 113997T).

Control of aflatoxigenic strains by Cinnamomum porrectum essential oil.

Essential oil from the bark of Cinnamomum porrectum (Roxb.) Kosterm was obtained by hydrodistillation using a Clevenger-type system for 3 h and identified by gas chromatography-mass spectrometry. The compounds were safrole (93.9%), elemicine (4.3%) and methyl eugenol (1.7%). The effect of essential oil on mycelial growth, sporulation, and aflatoxin B1 production of Aspergillus parasiticus IMI 283883 and Aspergillus flavus IMI 242684 was evaluated using contact and vapor treatments. Aflatoxin B1 was determined using the Enzyme-linked immunosorbent assay. The results showed that C. porrectum (Roxb.) Kosterm essential oil at concentrations more than 200 ppm exhibited inhibition effect on mycelial growth, sporulation, and aflatoxin B1 production of both Aspergillus strains as compared with control. The fumigation activities via vapor treatment showed higher inhibition than contact treatment. This study suggests that C. porrectum (Roxb.) Kosterm essential oil represents a good alternative in eco-friendly control of aflatoxigenic strain on food and agricultural commodities.

Additional paper waste in pulping sludge for biohydrogen production by heat-shocked sludge.

Dark anaerobic fermentation is an interesting alternative method for producing biohydrogen (H(2)) as a renewable fuel because of its low cost and various usable organic substrates. Pulping sludge from wastewater treatment containing plentiful cellulosic substrate could be feasibly utilized for H(2) production by dark fermentation. The objective of this study was to investigate the optimal proportion of pulping sludge to paper waste, the optimal initial pH, and the optimal ratio of carbon and nitrogen (C/N) for H(2) production by anaerobic seed sludge pretreated with heat. The pulping sludge was pretreated with NaOH solution at high temperature and further hydrolyzed with crude cellulase. Pretreatment of the pulping sludge with 3% NaOH solution under autoclave at 121 °C for 2 h, hydrolysis with 5 FPU crude cellulase at 50 °C, and pH 4.8 for 24 h provided the highest reducing sugar production yield (229.68 ± 2.09 mg/g(TVS)). An initial pH of 6 and a C/N ratio of 40 were optimal conditions for H(2) production. Moreover, the supplement of paper waste in the pulping sludge enhanced the cumulative H(2) production yield. The continuous hydrogen production was further conducted in a glass reactor with nylon pieces as supporting media and the maximum hydrogen production yield was 151.70 ml/g(TVS).

Kinetic comparison of microbial assemblages for the anaerobic treatment of wastewater with high sulfate and heavy metal contents.

Mixed-microbial assemblages enriched from a septic tank, coastal sediment samples, the digester sludge of a brewery wastewater treatment plant and acidic sulfate soil samples were compared on the basis of growth rate, waste and sulfate reduction rate under sulfate reducing conditions at 30 degrees C. The specific growth rate of various cultures was in the range 0.0013-0.0022 hr(-1). Estimates of waste and sulfate reduction rate were obtained by fitting substrate depletion and sulfate reduction data with the Michaelis-Menten equation. The waste reduction rates were in the range 4x10(-8)-1x10(-7) I mg(-1) hr(-1) and generally increased in the presence of copper, likely by copper sulfide precipitation that reduced sulfide and copper toxicity and thus protected the anaerobic microbes. Anaerobic microorganisms from a brewery digester sludge were found to be the most appropriate culture for the treatment of wastewater with high sulfate and heavy metal content due to their growth rate, and waste and sulfate reduction rate.

Effect of sulfate on the methanogenic activity of a bacterial culture from a brewery wastewater during glucose degradation.

The maximum specific methanogenic activity (SMA) of a sludge originating from a brewery wastewater treatment plant on the degradation of glucose was investigated at various levels of sulfate on a specific loading basis. Batch experiments were conducted in serum bottles at pH 7 and 35 degrees C. A comparison of the values indicates that the SMA of this mixed culture was increased and reached its highest level of 0.128 g CH4 gas COD/(g VSS x d) when biomass was in contact with sulfate at a ratio of 1:0.114 by weight.