青鳞鱼鱼肉提取物在加热过程中的性质研究

本文以青鳞鱼鱼肉为原料,采有冷水法和酶水解法制备提取物并对其在加热过程中的性质进行了研究。结果表明：①青鳞鱼鱼肉蛋白含量为68．3-71％且水溶性蛋白与水不溶性蛋白之比约为2：9;②酶水解法提取物非蛋白氮约为其总氮的50％．而冷水法提取物则为41．5％;③酶水解法提取物在50℃、60℃、70℃、80℃和90℃的温度条件下加热2h后．颜色明显加深,同时产生大量的呈香物质。但常规成分基本无变化;而冷水法提取物在同样的温度条件下,其颜色、滋味等感官特性变化不明显,但常规成分变化却明显;④提取物水溶性蛋白的变性温度为60—70℃,70—90℃时提取物总氮大部分是非蛋白氮。青鳞鱼提取物在加热过程中的这些性质为其加工和利用提供了重要的理论依据。     

Molecular cloning and dimorphic expression of growth hormone (gh) in female and male spotted scat Scatophagus argus

Spotted scat Scatophagus argus exhibits a typical sexual growth dimorphism in which the females grow faster than the males. Growth hormone (GH) is best known as an anterior pituitary hormone fundamental in regulating growth. To clarify the roles in sexual growth dimorphism in the spotted scat, gh cDNA was isolated from the pituitary. A phylogenetic tree was constructed based on the GH amino acid sequences of spotted scat and other vertebrates, and the resulting topology clearly reflects the taxonomic relationship of the Perciformes species selected. Alignment of GH amino acid sequences displayed very high similarity between the spotted scat and the other Perciformes species. The qRT-PCR analysis demonstrated that females exhibited higher pituitary gh mRNA levels than males at 6, 18, and 30 months (P < 0.05), which was 1.84, 4.61 and 6.34 times greater, respectively. In addition, immature males (6 months) exhibited higher pituitary gh mRNA levels than mature males (18 and 30 months). These results imply that the sexual growth dimorphism may be ascribable to the gh levels in pituitary in spotted scat.     

Stability comparison of three candidate internal reference genes in Chinese giant salamander (Andrias davidianus)

The Chinese giant salamander (Andrias davidianus) as food and medicinal product has been an important aquaculture object in China. Study of gene function in the Chinese giant salamander requires accurate normalization though the use of appropriate reference genes. In this study, the expression levels of three candidate reference genes including β‐actin, GAPDH and cytb of different tissues, different developmental stages and different challenges in Chinese giant salamander were evaluated by qPCR. The stabilities of these three reference genes were analysed by geNorm, NormFinder and BestKeeper software. The results showed that the expression of GAPDH was more stable than that of β‐actin and cytb in four tissues and at two developmental stages of Chinese giant salamander. Compared with GAPDH and cytb, β‐actin was the most stable in spleen of Chinese giant salamander treated with LPS or GSIV. Therefore, the result showed that GAPDH was the suitable reference gene in different tissues and at different developmental stages of Chinese giant salamander. The β‐actin could be used as a reference gene in spleen of Chinese giant salamander challenged with LPS and GSIV. This study provides convincing information for the GAPDH and β‐actin as suitable reference gene in Chinese giant salamander of different tissues, different developmental stages and different challenges respectively.     

PAC—IMBR工艺处理屠宰废水的试验研究

采用PAC-IMBR组合工艺处理屠宰废水,考察了该工艺对COD、BOD、NH3-N和浊度的去除效果。实验结果表明:组合工艺对COD、BOD和NH3-N的去除效果较好,去除率分别为95.56%、95.9%和91.1%,出水COD约为40 mg/L,NH3-N基本在10 mg/L以下,分别达到了《污水综合排放标准》(GB 8978-1996)的二级和一级标准;出水浊度<1 NTU,出水水质稳定。     

广东省水稻生产机械装备水平灰色预测与分析

利用广东省水稻生产主要环节机械装备保有量的历史数据,建立了灰色GM(1,1)预测模型,对2006-2020年广东省水稻生产机械装备水平进行了预测,并参考广东省水稻生产机械化作业水平值,对其预测结果进行了修正,以便能为政府主管部门制定提高水稻生产机械装备水平的政策措施提供参考依据.     

甜高粱茎秆残渣热裂解过程及其生物油成分分析

阐述了流化床反应器热裂解过程,以甜高粱茎秆残渣为生物质原料,在流化床反应器上进行了快速热裂解试验,并利用傅立叶变换红外光谱分析技术对产生的生物油化学成分进行了分析.结果表明:在500℃条件下的生物油产油率较高,为57%;生物油含有多种官能团和有机成分,主要有醇、酚、醚、酯及芳香烃类,是一种十分复杂的有机化合物的混合物.     

便携式割草机的设计

割草机是农、牧、园艺和园林等行业必备的一种常用机械,但适合面积狭小、形状不规则或地形复杂的地段且操作使用便捷、灵活的小型割草机却很少见.为此,在研究我国广泛应用的一些割草机技术的基础上,设计了简单实用的便携式割草机,其特点是结构简单、轻便、工作头前伸和支架高度可调;简要介绍了便携式割草机的总体结构、工作原理、电机选择及传动比的计算及刀片的设计.实验结果表明:该机具有操作容易、使用和携带方便、转向灵活等特点,能有效降低劳动强度.     

环保视阈下恩施州肥料利用问题及对策

指出了提高肥料利用率,减少肥料损失和对农业环境的污染是目前农业生产中急需解决的重要问题,针对恩施州有机肥用量不足、肥料投入结构不合理、肥料流失量较大、农业环境污染加重和边际效益下降等问题,提出了有机肥资源高效利用、采用新型科学施肥技术和减少环境污染的施肥技术等提高肥料利用率的建议。     

斑茅F1杂交可育亲本选择及其回交后代鉴定和主要经济性状

选用8个Badila(甘蔗热带种)与斑茅属间杂交F1品系与9个甘蔗栽培品种配制了24个回交组合，其中6个F1品系的13个组合杂交可育，共获346株BC1实生苗．经同工酶分析，其中320个株系具有斑茅的特征酶带，为斑茅的真实后代。在杂交可育性和BC1后代主要经济性状方面，斑茅F1品系间和杂交组合问均存在显著差异。斑茅BC1后代的产量性状和糖分仍与甘蔗栽培品种有较大差距，但各性状的最大值已与栽培品种的相当。初步研究结果表明，YC96—40和YC95—41是较好的斑茅F1亲本材料。     

猪流行性腹泻病毒云南省流行毒株S1基因序列分析

为深入了解云南省猪流行性腹泻病毒（porcine epidemic diarrhea virus,PEDV）的流行现状及现有疫苗株的保护效果,从2017—2022年云南省PEDV感染临床阳性样品中扩增出9份样品的PEDV S1基因,利用生物信息学方法,对9份样品S1基因进行了遗传进化树构建、同源性分析和氨基酸突变位点分析等。结果显示：2份样品位于G1基因群,其余7份位于G2基因群的G2b基因亚群。7份G2b基因亚群样品的核苷酸和推导氨基酸同源性较高,与G2基因群的AJ1102和L/W/L疫苗株处于不同基因亚群且同源性较低,并在第13、139、289和363位发生了不一致的突变位点;与现有疫苗株相比,在抗原中和位点COE区域以及其他区域,有明显的抗原性变化。结果表明：云南省存在G1基因群和G2b基因亚群PEDV同时流行,但以G2b基因亚群为主;流行株和疫苗株间存在较远的遗传和亲缘关系,以及氨基酸突变和抗原性差异,这很可能是导致目前PED控制不理想的原因,因此需要研发安全有效的疫苗。