RESUMEN
Establishing slash pine plantations is the primary method for restoring sandification land in the Houtian area of South China. However, the microbial variation pattern with increasing stand age remains unclear. In this study, we investigated microbial community structure and function in bare sandy land and four stand age gradients, exploring ecological processes that determine their assembly. We did not observe a significant increase in the absolute abundance of bacteria or fungi with stand age. Bacterial communities were dominated by Chloroflexi, Actinobacteria, Proteobacteria, and Acidobacteria; the relative abundance of Chloroflexi significantly declined while Proteobacteria and Acidobacteria significantly increased with stand age. Fungal communities showed succession at the genus level, with Pisolithus most abundant in soils of younger stands (1- and 6-year-old). Turnover of fungal communities was primarily driven by stochastic processes; both deterministic and stochastic processes influenced the assembly of bacterial communities, with the relative importance of stochastic processes gradually increasing with stand age. Bacterial and fungal communities showed the strongest correlation with the diameter at breast height, followed by soil available phosphorus and water content. Notably, there was a significant increase in the relative abundance of functional groups involved in nitrogen fixation and uptake as stand age increased. Overall, this study highlights the important effects of slash pine stand age on microbial communities in sandy lands and suggests attention to the nitrogen and phosphorus requirements of slash pine plantations in the later stages of sandy management.
Asunto(s)
Microbiota , Pinus , Pinus/microbiología , Arena , Microbiología del Suelo , Suelo/química , Bacterias , China , FósforoRESUMEN
The study on the extraction conditions, purification, and biological activity of slash pine (Pinus elliottii.) is important for the development of slash pine resources. The optimal process conditions for the extraction of slash pine polysaccharide (SPP) were determined, resulting in a liquid-solid ratio of 66.94 mL/g, extraction temperature of 83.74 °C and extraction time of 2.56 h by using the response surface methodology, and the yield of SPP was 5.99% under the optimized conditions. Following the purification of SPP, the SPP-2 component was obtained and its physicochemical properties, functional group composition, antioxidant capacity, and moisturizing capacity were determined. Structural analysis suggested that SPP-2 has a molecular weight of 118.407 kDa, and was composed of rhamnose, arabinose, fucose, xylose, mannose, glucose, and galactose in a ratio of 5.98: 14.34: 1: 1.75: 13.50: 3.43: 15.79. The antioxidant activity analysis showed that SPP-2 has good free radical scavenging activity, and it was also found to have in vitro moisturizing activity and low irritation. These results suggest that SPP-2 has the potential for applications in the pharmaceutical, food, and cosmetic industries.