[Screening of extreme salt-alkali tolerant strain and effect of its fertilizer on wheat growth and soil environment under saline-alkali condition.] / æžç«¯è€ç›ç¢±èŒæ ªçš„ç­›é€‰åŠå ¶èŒè‚¥å¯¹ç›ç¢±æ¡ä»¶ä¸‹å°éº¦ç”Ÿé•¿å’ŒåœŸå£¤çŽ¯å¢ƒçš„å½±å“.

To obtain salt-alkali tolerant strains which could be potenially used to improve the quality of saline-alkali soil, soil samples collected from Dongying, Shandong Province were diluted and spread to modified Gibbson medium with pH 9 and salt concentration of 100 g·L-1. A total of 18 bacteria strains were obtained. By increasing salt concentration and pH, an extremely salt-alkali tole-rant strain N14 was screened which could grow at pH 12 and salt concentration of 20%. We analyzed the morphological, physiological and biochemical characters and 16S rDNA sequence of N14. The strain N14 was identified as Bacillus marmarensis. N14 bacterial fertilizer significantly increased the biomass of wheat, improved shoot height, fresh weight and dry weight by 21.8%, 57.9% and 41.7%, respectively. The addition of N14 bacterial fertilizer significantly increased the chlorophyll a, chlorophyll b and total chlorophyll in wheat by 36.4%, 20.0% and 31.7%, respectively. It significantly increased the activities of invertase, urease and alkaline phosphatase in saline-alkali soil by 23.2%, 68.8% and 106.5%, respectively. It also significantly increased the activities of superoxide dismutase, peroxidase and catalase in roots by 109.6%, 17.8% and 50%, respectively. The concentration of malondialdehyde in wheat roots was significantly reduced by 39.8%. This study provided an idea for the application of extreme salt-alkali tolerant bacteria and a way for improvement of saline-alkali soil.

Screening of bacteria that antagonize the main pathogen fungi of apple replantation disorders from anaerobic fermented fluid of organic material and its inhibitory effect.

Anaerobic fermented organic materials fluid (AFOF) could alleviate apple replant diseases. In this study, bacteria from AFOF was screened which could antagonize the main pathogenic fungi (Fusarium solani, F. proliferatum, F. oxysporum, F. moniliforme). The effects of the antagonistic bacteria were verified by pot experiment. The results showed that AFOF could significantly inhibit the pathogenic fungi growth and reproduction. Four strains (L11, L12, L13, L14) with strong inhibition activity were obtained from AFOF by the confrontation test, with the highest inhibitory rate being up to 57.3%. All the four strains were Bacillus, with no obvious antagonism each other. Both antagonistic bacteria and methyl bromide fumigation could promote the biomass of Malus hupenhensis seedling compared with continuous cropping soil. Methyl bromide fumigation led to the best growth of M. hupenhensis seedling. The antagonistic bacteria cloud improve root activity, with root length and root tip number increased by 25.1% and 70.9%, respectively. Compared with the continuous cropping soil, antagonistic bacteria and methyl bromide fumigation effectively decreased soil fungi by 71.2% and 64.2%, respectively. Treatment with antagonistic bacteria increased soil bacteria and soil actinomycetes by 48.0% and 140.2%, respectively, indicating that soil microbial community was transformed to "bacteriatype". Treatment with methyl bromide fumigation could significantly reduce soil bacteria and soil actinomycetes, suggesting the antagonistic bacteria could inhibit the growth of pathogenic fungi in soil.

Spatiotemporal distribution and determinants of gonorrhea infections in mainland China: a panel data analysis.

OBJECTIVES: Gonorrhea remains a major public health concern worldwide. This study aims to explore the spatiotemporal distribution and sociodemographic determinants of gonorrhea rates during 2004-2014 in mainland China. STUDY DESIGN: Space-time scan statistics and spatial panel regression model. METHODS: The gonorrhea infection data and sociodemographic data during 2004-2014 at the provincial level in mainland China were extracted from the China Public Health Science Data Center and China Statistical Yearbooks, respectively. The space-time scan statistics were used to identify the high-risk clusters of gonorrhea, and the spatial panel regression model was adopted to examine the sociodemographic determinants. RESULTS: One most likely and five secondary high-risk clusters of gonorrhea rates were identified, which were mainly located in southern and eastern China. The regions with higher GDP per capita, larger floating population, less access to healthcare, higher male-female ratio, and higher divorce rate were more likely to become high-risk areas of gonorrhea. CONCLUSIONS: Gonorrhea rates were distributed unevenly through space and time and affected by various sociodemographic variables. The space-time scan statistics and spatial panel regression are viable tools for identifying clusters and examining determinants of gonorrhea rates. The findings provide valuable implications for developing targeted prevention and control programs in public health practice.