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A novel actinomycete strain ET3-3T isolated from soil collected from Chachoengsao province, Thailand was taxonomic evaluated using a polyphasic approach. Chemotaxonomic analysis indicated that meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. Mycolic acids were present. Ribose, arabinose, and galactose were detected in its whole-cell hydrolysates. The strain comprised C16:0 and TBSA 10-methyl C18:0 as the main fatty acids and MK-8(H4ω-cycl) as the predominant menaquinone. Major polar lipids were phosphatidylinositol, phosphatidylinositol mannoside, phosphatidylethanolamine, and diphosphatidylglycerol. The results of 16S rRNA gene sequence analysis showed that strain ET3-3T was closely related to Nocardia seriolae JCM 30082T (99.2%), Nocardia yunnanensis JCM 30082T (98.4%), and Nocardia concava JCM 12351T (98.2%). The draft genome of ET3-3T was 9.31 Mb with 8826 coding sequences with an average G + C content of 68.0%. The comparison of the draft genome of strain ET3-3T and N. seriolae NBRC 15557T showed the ANIb, ANIm and the digital DNA-DNA hybridization values of 86.3%, 88.5% and 32.9%, respectively. The results of the taxonomic analysis suggested that strain ET3-3T represented a novel species of the genus Nocardia for which the name Nocardia terrae sp. nov. is proposed. The type strain is ET3-3T (= JCM 33776T = TISTR 2837T). [ABSTRACT FROM AUTHOR]

Two strains of yeast-like achlorophyllous alga belonging to the genus Prototheca were isolated from the water and soil, respectively, from a mangrove forest in Thailand. Cultures of both strains were achlorophyllous when grown under light and dark conditions, and they reproduced by release of sporangiospores. Phylogenetic analyses, based on the D1/D2 region of the large subunit ribosomal RNA gene and the small subunit ribosomal RNA gene nucleotide sequences, revealed these two strains were closely related to Prototheca cutis. The strains grew well at 25 °C, weakly or slowly at 30 °C, but not at 35 °C and higher, and were found to be susceptible to 50 μg/disk clotrimazole, as determined by the disk diffusion test. They assimilated a limited number of carbon/nitrogen compounds; glucose, galactose, trehalose, ethanol, glycerol, propylene glycol, lactic acid, fructose and mannose as sole sources of carbon, and ammonium, lysine and cadaverine as sole sources of nitrogen. The two strains are clearly distinguished from P. cutis by the abilities to assimilate polypropylene glycol and the inability to grow at 35 °C and higher. In this study, the ninth member of the genus Prototheca, Prototheca paracutis sp. nov. (ex-type strain YMTW3-1T = JCM 32112T = TBRC8745T), is proposed. The MycoBank number is MB 821626. In addition, P. paracutis sp. nov. was observed to accumulate lipid at up to 21% of the cell dry weight, characterizing it as an oleaginous microorganism. • Two strains of Prototheca, achlorophyllous microalga, were isolated from mangrove. • Prototheca paracutis sp. nov. is proposed to accommodate the two strains. • Prototheca paracutis produced a substantial amount of intracellular lipids. [ABSTRACT FROM AUTHOR]

Nitrogen (N) fixed by termites was evaluated as a N input to decomposition processes in two tropical forests, a dry deciduous forest (DDF) and the neighboring dry evergreen forest (DEF), Thailand. A diverse group of termite species were assayed by acetylene reduction method and only the wood/litter-feeding termites were found to fix N. More intensive samplings of two abundant species, Microcerotermes crassus and Globitermes sulphureus, were done across several seasons, suggesting N fixation rates of 0.21 and 0.28 kg ha−1 y−1 by termites in the DDF and DEF, respectively. Also, estimates of asymbiotic N fixation rates were 0.75 and 3.95 kg ha−1 y−1. N fixed by termites and by asymbiotic fixers is directly supplied to decomposers breaking down dead plant material and could be a major source of their N. N fixed by termites was 7–22% of that fixed by termites and asymbiotic fixers. Although N fixed by termites is a small input compared to other inputs, this N is likely important for decomposition processes. [ABSTRACT FROM AUTHOR]

A role of termites in decomposition processes was quantitatively evaluated in a dry evergreen forest (DEF) in Thailand, using respiration rates and biomasses of fungus combs as well as of termites themselves. The termite population and fungus combs mineralized 11.2% of carbon (C) in the annual aboveground litterfall (AAL) by their respiration. Fungus combs were responsible for a major part (7.2% of the AAL) of the C mineralization mediated by termites. For comparison, fractions of AAL mineralized by respiration from termite populations and fungus combs were estimated for tropical forests and savannas where termites have been well studied, assuming that there is the same ratio as for the DEF between biomass of fungus combs and abundance of fungus growers. Termites in dry tropical forests (annual rainfall<2,000 mm) are shown to mineralize about 10% of C in the AAL by respiration from their populations and fungus combs, and their ecological impact in savannahs is comparable in this aspect. A significant negative correlation between fraction of AAL and annual rainfall demonstrates that the importance of termites in decomposition processes is greater in dry tropical forests than in moist tropical forests. Considering that fungus combs contributed significantly to AAL mineralization in most of the tropical forests and savannas, fungus growers are a much more influential group than previously expected in tropical ecosystems. [ABSTRACT FROM AUTHOR]

A correction to this paper has been published: https://doi.org/10.1007/s00203-021-02372-w [ABSTRACT FROM AUTHOR]