Abstract Prodigiosin, a secondary metabolite extracted from Serratia marcescens (S. marcescens), could induce apoptosis in various cancer cells, with however low toxicity on normal cells. The red pigment was extracted from a strain S. marcescens NJZT-1 isolated from soil, which had antibacterial activity. Spectral analyses (LC-ESI-MS, UV-VIS spectrophotometry, infrared spectra and HPLC) and TLC indicated the presence of prodigiosin in the extracellular bacterial culture extracts. The red pigment effectively killed the TSC2-null cells, whose mutation resulted in the progressive and systemic disease LAM. Our findings provide interesting evidence and important basis for the development of new therapeutic compounds with high potential effects against TSC2-null cells.

ABSTRACT No-tillage and straw returning are important practices for preserving and improving soil quality for the sustainable management system. The experimental field was established in 2007 with conventional tillage (CT), conventional tillage with straw returning (CTS), no-tillage (NT), and no-tillage with straw returning (NTS) practice in rice (Oryza sativa L.)-rape (Brassica napus L.) cropping system. The soil samples were collected in 2013-2015 from 0-20 and 20-40 cm depth to investigate the effects on soil organic C (SOC), water-stable aggregation (> 5, 5-2, 2-1, 1.0-0.5, 0.25-0.5, and < 0.25 mm), and their stability in paddy soil of the central China. In the last year (2015), the integrative use of no-tillage and straw returning significantly increased SOC content and contribution of the macroaggregates in 0-20 cm and microaggregates in 20-40 cm depth. Compared with CT, SOC content, mean weight diameter (MWD), geometric mean diameter (GMD), and fractal dimensions (FD) under NTS were increased 25%, 21%, 19%, and 12%, respectively, in the 0-20 cm depth. In 20-40 cm depth, the soil micro-aggregates were higher under CTS treatment. Percentages of macroaggregates and microaggregates under NTS were increased 60% and 40% in the 0-20 cm depth. The SOC had positive linear relationship with MWD, GMD, > 5, 2-5, 1-2, and 0.25-0.5 mm aggregates. Thus, long-term combine use of NT with straw returning practices significantly improved SOC and water-stable aggregation. No-tillage and straw returning appeared to be promising and sustainable strategies to conserve SOC sequestration and stable soil aggregates in rice-rape cropping system.

Five strains of fungi and 18 strains of bacteria were isolated from the soil and horse manure with cellulose as the sole carbon source. Among them, two fungal, F9 and F13, and two bacterial, B16 and B21, showed the highest filter paper activities, which were 7.79 U g-1, 9.84 U g-1, 7.34 U g-1 and 9.68 U g-1, respectively. Four microbial systems, designed as FH1 (F13+B21), FH2 (F13+B16+B21), FH3 (F9+B16+B21) and FH4 (F13+F9+B16+B21) were developed. The fermentation studies showed that the filter paper activity of the composite microbial system FH3 was higher than the others, which was 21.34 U g-1. The medium with bran and filter paper as the carbon source and peptone as nitrogen source was optimal and the maximum cellulase activity was reached at 30~35ºC and pH 6.0~6.5 when FH3 was incubated for 48 h. The enzymatic reaction conditions were estimated at 45~55 ºC, pH 4.5~5.5 and the thermal stability temperature was up to 60 ºC.