The massive amount of sodium silicate in the used sand was a pollution source,especially in the waste water from the wet reclamation of used sand.A new process of wet reclamation by biologically treating the waste wat...The massive amount of sodium silicate in the used sand was a pollution source,especially in the waste water from the wet reclamation of used sand.A new process of wet reclamation by biologically treating the waste water produced during the wet reclamation process of used sand was studied in the paper.In the work,the pre-cultivation of N.palea was performed firstly,and three different scrubbing solutions:(1) tap water,(2) modified medium for N.palea,and (3) filtrate of the broth treated by N.palea for 15 days,were used.The results of the primary investigation show that a de-skinning ratio of 90% is obtained when using the scrubbing solution containing modified medium for N.palea at the ratio 1:2 of sand and scrubbing solution,and the maximal concentrations of Na+ and SiO32are 1.49 g·L-1 and 0.51 g·L-1,respectively.The results of the optimal biomass,pH value decrease and Na+ and SiO32consumption indicate the optimal incubation conditions are at the irradiance of 5,000 lux and 25 oC.Using the filtrate of the broth treated by N.palea for 15 days as the scrubbing solution directly,a de-skinning ratio of 93% is the highest compared to the results of the tap water and the modified medium for N.palea.In the biological process using N.palea,less water is used and little wastewater is produced,which is advantageous to the purpose of green manufacturing and environmental protection.展开更多
The palea and lemma are floral organ structures unique to grasses;these structures form the hull and directly affect grain size and quality. However, the molecular mechanisms controlling the development of the hull ar...The palea and lemma are floral organ structures unique to grasses;these structures form the hull and directly affect grain size and quality. However, the molecular mechanisms controlling the development of the hull are not well understood. In this study, we characterized the rice(Oryza sativa) abnormal flower and grain1(afg1) mutant, a new allele of OsMADS6. Similar to previously characterized osmads6 alleles, in the afg1 floret, the palea lost its marginal region and acquired the lemma identity. However, in contrast to other osmads6 alleles, the afg1 mutant showed altered grain size and grain quality, with decreased total starch and amylose contents, and increased protein and soluble sugar contents. The analysis of transcriptional activity suggested that AFG1 is a transcriptional activator and may affect grain size by regulating the expression levels of several genes related to cell expansion and proliferation in the afg1 mutant. These results revealed that AFG1 plays an important role in determining palea identity and affecting grain yield and quality in rice.展开更多
Critical algal blooms in great lakes increase the level of algal organic matters（AOMs）,significantly altering the composition of natural organic matters（NOMs） in freshwater of lake.This study examined the AOM＇s c...Critical algal blooms in great lakes increase the level of algal organic matters（AOMs）,significantly altering the composition of natural organic matters（NOMs） in freshwater of lake.This study examined the AOM＇s characteristics of Nitzschia palea（N.palea）,one kind of the predominant diatom and an important biomarker of water quality in the great lakes of China,to investigate the effect of AOMs on the variation of NOMs in lakes and the process of algal energy.Excitation–emission matrix fluorescence（EEM） spectroscopy,synchronous fluorescence（SF） spectroscopy and deconvolution UV–vis（D-UV） spectroscopy were utilized to characterize AOMs to study the effects of nutrient loading on the composition change of AOMs.From results,it was revealed that the phosphorus is the limiting factor for N.palea＇s growth and the generation of both total organic carbon and amino acids but the nitrogen is more important for the generation of carbohydrates and proteins.EEM spectra revealed differences in the composition of extracellular organic matter and intracellular organic matter.Regardless of the nitrogen and phosphorus concentrations,aromatic proteins and soluble microbial products were the main components,but the nitrogen concentration had a significant impact on their composition.The SF spectra were used to study the AOMs for the first time and identified that the protein-like substances were the major component of AOMs,creating as a result of aromatic group condensation.The D-UV spectra showed carboxylic acid and esters were the main functional groups in the EOMs,with –OCH_3,–SO_2NH_2,–CN,–NH_2,–O– and –COCH_3functional groups substituting into benzene rings.展开更多
【目的】了解山瑞鳖红底板病的病原菌及其对药物的敏感性,为生产中有效防治该病提供科学依据。【方法】以常规方法从患红底板病山瑞鳖的肝脏、心脏和腹水中分离病菌,人工感染确定其致病性,以API 20NE生化鉴定与16S r RNA基因序列分析相...【目的】了解山瑞鳖红底板病的病原菌及其对药物的敏感性,为生产中有效防治该病提供科学依据。【方法】以常规方法从患红底板病山瑞鳖的肝脏、心脏和腹水中分离病菌,人工感染确定其致病性,以API 20NE生化鉴定与16S r RNA基因序列分析相结合的方法鉴定病原菌,并采用K-B纸片扩散法进行药敏试验。【结果】从患病山瑞鳖的心脏、肝脏和腹水中分离到3株优势菌株,经鉴定均为嗜水气单胞菌(Aeromonas hydrophila),与标准株ATCC 7966的亲缘关系最近,同源性达99.6%。3株病原菌对舒普深、菌必治、多粘菌素B和先锋必等4种药物均高度敏感,而对先锋霉素VI、青霉素G和氨苄青霉素等3种药物均不敏感。【结论】引起广西南宁市某养鳖场山瑞鳖红底板病的病原菌是嗜水气单胞菌,可选用舒普深、菌必治、多粘菌素B和先锋必等药物进行治疗。放养密度大、水质条件差和相互咬伤是山瑞鳖在保温越冬期间红底板病暴发性流行的诱发因子。展开更多
基金financially supported by the National Natural Science Foundation of China (No.51075163)the Research Fund for the Doctoral Program of Higher Education of China (No.20100142110017)
文摘The massive amount of sodium silicate in the used sand was a pollution source,especially in the waste water from the wet reclamation of used sand.A new process of wet reclamation by biologically treating the waste water produced during the wet reclamation process of used sand was studied in the paper.In the work,the pre-cultivation of N.palea was performed firstly,and three different scrubbing solutions:(1) tap water,(2) modified medium for N.palea,and (3) filtrate of the broth treated by N.palea for 15 days,were used.The results of the primary investigation show that a de-skinning ratio of 90% is obtained when using the scrubbing solution containing modified medium for N.palea at the ratio 1:2 of sand and scrubbing solution,and the maximal concentrations of Na+ and SiO32are 1.49 g·L-1 and 0.51 g·L-1,respectively.The results of the optimal biomass,pH value decrease and Na+ and SiO32consumption indicate the optimal incubation conditions are at the irradiance of 5,000 lux and 25 oC.Using the filtrate of the broth treated by N.palea for 15 days as the scrubbing solution directly,a de-skinning ratio of 93% is the highest compared to the results of the tap water and the modified medium for N.palea.In the biological process using N.palea,less water is used and little wastewater is produced,which is advantageous to the purpose of green manufacturing and environmental protection.
基金supported by the Zhejiang Natural Science Foundation(LY18C130007)the National Natural Science Foundation of China(91735304)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund of China National Rice Research Institute(2017RG001-4)the National Science and Technology Major Project(2016ZX08009003-003-008)。
文摘The palea and lemma are floral organ structures unique to grasses;these structures form the hull and directly affect grain size and quality. However, the molecular mechanisms controlling the development of the hull are not well understood. In this study, we characterized the rice(Oryza sativa) abnormal flower and grain1(afg1) mutant, a new allele of OsMADS6. Similar to previously characterized osmads6 alleles, in the afg1 floret, the palea lost its marginal region and acquired the lemma identity. However, in contrast to other osmads6 alleles, the afg1 mutant showed altered grain size and grain quality, with decreased total starch and amylose contents, and increased protein and soluble sugar contents. The analysis of transcriptional activity suggested that AFG1 is a transcriptional activator and may affect grain size by regulating the expression levels of several genes related to cell expansion and proliferation in the afg1 mutant. These results revealed that AFG1 plays an important role in determining palea identity and affecting grain yield and quality in rice.
基金the support of Fundamental Research Funds for the Central Universities (No.2015ZCQ-HJ-02)the National Natural Science Foundation of China (Nos.51578520,51378063,41273137 and 51108030)+1 种基金the Beijing Natural Science Foundation (No.8132033)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology (No.QAK201306)
文摘Critical algal blooms in great lakes increase the level of algal organic matters（AOMs）,significantly altering the composition of natural organic matters（NOMs） in freshwater of lake.This study examined the AOM＇s characteristics of Nitzschia palea（N.palea）,one kind of the predominant diatom and an important biomarker of water quality in the great lakes of China,to investigate the effect of AOMs on the variation of NOMs in lakes and the process of algal energy.Excitation–emission matrix fluorescence（EEM） spectroscopy,synchronous fluorescence（SF） spectroscopy and deconvolution UV–vis（D-UV） spectroscopy were utilized to characterize AOMs to study the effects of nutrient loading on the composition change of AOMs.From results,it was revealed that the phosphorus is the limiting factor for N.palea＇s growth and the generation of both total organic carbon and amino acids but the nitrogen is more important for the generation of carbohydrates and proteins.EEM spectra revealed differences in the composition of extracellular organic matter and intracellular organic matter.Regardless of the nitrogen and phosphorus concentrations,aromatic proteins and soluble microbial products were the main components,but the nitrogen concentration had a significant impact on their composition.The SF spectra were used to study the AOMs for the first time and identified that the protein-like substances were the major component of AOMs,creating as a result of aromatic group condensation.The D-UV spectra showed carboxylic acid and esters were the main functional groups in the EOMs,with –OCH_3,–SO_2NH_2,–CN,–NH_2,–O– and –COCH_3functional groups substituting into benzene rings.
