Abstract: Cordyceps militaris is a valuable medicinal fungus and has been widely cultivated. However, its frequent degeneration during continuous maintenance in culture leads to a dramatic reduction in productivity and cordycepin content in the fruiting body. Mating-type (MAT) genes play an important role in the formation of the fruiting body in C. militaris. The data of MATgenes, the productivity and quality of C. militaris strains being cultivated in Vietnam are the foundations for providing solutions to overcome the problem. In this study, eight strains were isolated and identified based on morphological characteristics and the ITS sequence of rDNA. MAT1-1-1 and MAT1-2-1 genes were determined in the 8 isolates, including 5 strains (QN6, HL11, HL12, TN01, and TN02) that possessed both MAT1-1-1 and MAT1-2-1 genes and the others (SH03, HL13, and HN01) has only MAT1-1-1 gene. All identified strains were able to form a fruiting body, especially, the SH03 strain performed the highest productivity and quality (fruiting body yield 31 g/box, biological efficiency 13.77% and cordycepin content 12.5 mg/g dried fruiting body). This fungal strain with a single mating-type gene is a promising candidate for applying to C. militarisproduction.

Abstract: Temperature and light are important factors for the growth of photoautotrophic microorganisms such as Spirulina maxima; therefore, proper control of these conditions in S. maxima’s culture will help to enhance production efficiency. This study aims to determine the effect of temperature (in the range of 15-40oC) and LED lights (white and red) on the growth, pigment content and biological activities of S. maxima biomass. The findings showed that the most suitable temperature rangefor growing S. maxima was about 25-30ºC. After ten days of cultivating with both white and red LEDs, the highest dry weight biomass reached 1.705 and 1.891 g/l, respectively. However, the ability to accumulate pigments like phycocyanin, chlorophyll, and carotenoids in the dry biomass cultured under the red LEDs was 152.0, 6.6, and 3.0 mg/g, respectively, which are higher than that under the white LEDs (118.0, 5.5, and 2.9 mg/g, respectively). In addition, S. maxima extracts from the biomass cultured under the red LEDs exhibited antibacterial activity against two pathogenic strains Staphylococcus aureusVTCC12275 and Escherichia coli VTCC12272, as well as the ability to scavenge free radicals by DPPH, are also better than those grown under the white LEDs.

Abstract: Two Permian-Triassic boundary (PTB) successions, Lung Cam in Vietnam, and Lukač in Slovenia, have been sampled for high-resolution magnetic susceptibility, stable isotope and elemental chemistry, and biostratigraphic analyses. These successions are located on the eastern (Lung Cam section) and western margins (Lukač section) of the Paleo-Tethys Ocean during PTB time. Lung Cam, lying along the eastern margin of the Paleo-Tethys Ocean provides an excellent proxy for correlation back to the GSSP and out to other Paleo-Tethyan successions. This proxy is tested herein by correlating the Lung Cam section in Vietnam to the Lukač section in Slovenia, which was deposited along the western margin of the Paleo-Tethys Ocean during the PTB interval. It is shown herein that both the Lung Cam and Lukač sections can be correlated and exhibit similar characteristics through the PTB interval. 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