Taurine alone or in combination with fish protein hydrolysate affects growth performance,taurine transport and metabolism in juvenile turbot (Scophthalmus maximus L.)

The study was conducted to investigate the effects of taurine (Tau) alone or in combination with fish protein hydrolysate (FPH) on growth performance, the expression of Tau transporter (TauT) and metabolic profile in juvenile turbot. FM, FPH0, FPH0+T, FPH10 and FPH10+T diets, respectively, contained 300, 150, 150, 80, and 80 g/kg fishmeal. FPH10 and FPH10+T diets contained 62 g/kg FPH. FPH0+T and FPH10+T diets were, respectively, prepared by supplementing the FPH0 and FPH10 diet formulations with 8 g/kg Tau. Specific growth rate was the highest in FM group and the lowest in FPH10 group. TauT mRNA levels in fish fed Tau supplemented diets were significantly lower than that in Tau unsupplemented diets. NMR‐based metabolomics analysis showed that Tau contents in liver of FPH0+T and FPH10+T were significantly higher than that of FM, FPH0 and FPH10. In muscle, Tau contents were significantly decreased in the FPH10+T versus FPH0 and the FPH10+T versus FPH10 comparisons. In conclusion, 62 g/kg FPH to replace fishmeal may not affect Tau synthesis, transport and metabolism. However, Tau supplemented alone or in combination with a certain level of FPH could reduce the requirement for Tau synthesis and transport and increased Tau levels in muscle and liver.     

关中奶山羊睾丸不同发育阶段代谢物的差异分析

【目的】 试验旨在从代谢组学角度探究关中奶山羊睾丸发育代谢机制。【方法】 选择1月龄断奶雄性关中奶山羊和24月龄体成熟的雄性关中奶山羊各6只,采集睾丸组织,使用液相色谱-质谱（LC-MS）技术对睾丸组织进行化学检测,通过多维和单维分析相结合的方式对两组不同代谢物进行化学检测、对比与鉴别,通过富集差异代谢物分析筛选关中奶山羊发育代谢中的潜在关键通路。【结果】 在1和24月龄关中奶山羊睾丸组织中共筛选出334个差异代谢物,其中显著上调137个,显著下调197个。对前36个差异代谢物进行比较鉴定发现,分别为脂质和类脂质分子、有机酸及其衍生物、未分类化合物和苯丙烷和聚酮化合物四大类。经相关性分析发现,在1和24月龄关中奶山羊睾丸发育过程中,脂质和类脂质分子与甘油磷脂呈最大正相关,羧基及其衍生物与甘油磷脂呈最大负相关。对不同的代谢物进行富集分析,筛选出7条潜在的重要代谢通路,分别为肿瘤中的胆碱代谢、精氨酸和脯氨酸代谢、肿瘤中的中心碳代谢、铁死亡、谷胱甘肽代谢、氨酰-tRNA生物组成以及牛磺酸和亚牛磺酸代谢。【结论】 本试验从代谢组学角度揭示了1和24月龄关中奶山羊睾丸的差异代谢物及代谢机制,为今后哺乳动物睾丸的发育研究奠定了基础。     

基于血浆非靶代谢组学探究急性笼养应激对蛋鸭代谢的影响

随着环保政策改革和养殖业的集约化、规模化发展,蛋鸭叠层式笼养模式的应用越来越广泛,笼养应激对蛋鸭的影响逐渐受到重视。本研究旨在利用非靶向代谢组学分析蛋鸭平养与笼养模式下血浆代谢物的差异。随机挑选平养组(floor-water rearing system, FWR组)和叠层式笼养组(cage-rearing system, CR组)蛋鸭各10只,跖骨静脉采血,通过高效液相色谱-质谱(HPLC-HRMS)非靶向代谢组学技术获得20个在不同饲养模式下的血浆代谢物图谱,经T检验等分析,取差异倍数(Fold-change)ratio≥2或ratio≤1/2、变量重要性(variable importance in projection, VIP)>1、q值<0.05为筛选条件得到显著差异代谢物并作通路富集分析。结果共筛选到差异代谢物30种,其中上调表达的差异代谢物14种(P<0.05),下调表达的差异代谢物16种(P<0.05)。差异代谢物种类主要有甘油磷脂(glycerophospholipids, 16种)、脂肪酰基(fatty acyls, 4种)、羧酸及其衍生物...     

Untargeted UHPLC–Q-Exactive-MS-based metabolomics reveals associations between pre- and post-cooked metabolites and the taste quality of geographical indication rice and regular rice

Geographical indication (GI) rice refers to the rice of specific geographical origin, which tends to have a good taste quality and a high commodity price. Rice is favored for its soft texture and chewiness after cooking. However, GI rice is also plagued by rice fraud. Understanding the reasons for the excellent taste quality of GI rice and identifying its geographical origin can help maintain the stability of the rice market and promote the development of the rice industry. In this study, we determined the taste quality of rice. Untargeted metabolomics based on UHPLC–Q-Exactive-MS was used to identify metabolites in GI and regular rice before and after cooking. Our findings suggested that GI rice showed lower protein and amylose content, resulting in higher starch gelatinization properties and taste quality. This study identified 520 metabolites, among which 142 and 175 were significantly different between GI and regular rice, before and after cooking, respectively. The increased variety of metabolites after cooking was significantly negatively correlated with the taste quality of rice. GI rice was lower in amino acids and lipid metabolite content before and after cooking, which may be the reason for the excellent taste quality. Through linear discriminant analysis, we found that the differential metabolites of rice after cooking were more accurate in discriminating rice from different geographic origins, up to 100%. This work gained new insights into the metabolites of GI rice, which explains its excellent taste quality. The rice metabolites after cooking could be used for more accurate geographical identification of rice.     

Mixotrophy in a Local Strain of Nannochloropsis granulata for Renewable High-Value Biomass Production on the West Coast of Sweden

A local strain of Nannochloropsis granulata (Ng) has been reported as the most productive microalgal strain in terms of both biomass yield and lipid content when cultivated in photobioreactors that simulate the light and temperature conditions during the summer on the west coast of Sweden. To further increase the biomass and the biotechnological potential of this strain in these conditions, mixotrophic growth (i.e., the simultaneous use of photosynthesis and respiration) with glycerol as an external carbon source was investigated in this study and compared with phototrophic growth that made use of air enriched with 1–2% CO₂. The addition of either glycerol or CO₂-enriched air stimulated the growth of Ng and theproduction of high-value long-chain polyunsaturated fatty acids (EPA) as well as the carotenoid canthaxanthin. Bioassays in human prostate cell lines indicated the highest antitumoral activity for Ng extracts and fractions from mixotrophic conditions. Metabolomics detected betaine lipids specifically in the bioactive fractions, suggesting their involvement in the observed antitumoral effect. Genes related to autophagy were found to be upregulated by the most bioactive fraction, suggesting a possible therapeutic target against prostate cancer progression. Taken together, our results suggest that the local Ng strain can be cultivated mixotrophically in summer conditions on the west coast of Sweden for the production of high-value biomass containing antiproliferative compounds, carotenoids, and EPA.     

Investigation of Interspecies Interactions within Marine Micromonosporaceae Using an Improved Co-Culture Approach

With respect to bacterial natural products, a significant outcome of the genomic era was that the biosynthetic potential in many microorganisms surpassed the number of compounds isolated under standard laboratory growth conditions, particularly among certain members in the phylum Actinobacteria. Our group, as well as others, investigated interspecies interactions, via co-culture, as a technique to coax bacteria to produce novel natural products. While co-culture provides new opportunities, challenges exist and questions surrounding these methods remain unanswered. In marine bacteria, for example, how prevalent are interspecies interactions and how commonly do interactions result in novel natural products? In an attempt to begin to answer basic questions surrounding co-culture of marine microorganisms, we have tested both antibiotic activity-based and LC/MS-based methods to evaluate Micromonosporaceae secondary metabolite production in co-culture. Overall, our investigation of 65 Micromonosporaceae led to the identification of 12 Micromonosporaceae across three genera that produced unique metabolites in co-culture. Our results suggest that interspecies interactions were prevalent between marine Micromonosporaceae and marine mycolic acid-containing bacteria. Furthermore, our approach highlights a sensitive and rapid method for investigating interspecies interactions in search of novel antibiotics, secondary metabolites, and genes.     

南美油藤种子发育过程的代谢组学和转录组学联合分析

【目的】南美油藤种子油中富含不饱和脂肪酸,是一种具有重要经济价值和应用前景的油料植物。目前影响南美油藤种子油脂合成的关键基因、途径及其调控机理尚未清晰。因此,对南美油藤种子的脂质代谢物的动态变化规律及重要脂肪酸代谢相关调控基因的研究,不仅能够为提高其种子油产量和改善油脂品质提供理论基础,也可为其他木本油料植物高效开发利用提供有价值的参考依据。【方法】选用不同生长阶段的南美油藤种子(形成初期、发育初期、中期、后期、成熟期)为研究对象,结合GC-MC代谢组学技术和高通量转录组测序技术,分析种子发育过程中脂质代谢物含量的动态变化规律,并根据种子不同生长阶段的差异表达基因寻找出脂质代谢物生物合成与累积的关联酶基因。【结果】脂质代谢组学分析发现,南美油藤种子中高含量的α-亚麻酸和亚油酸主要在种子成熟阶段合成与累积,是判别南美油藤种子中脂肪酸缓慢累积时期与快速累积阶段的依据。转录组学分析表明,南美油藤种子成熟阶段前后的基因表达存在显著差异。结合代谢组学与转录组学的分析结果显示,与脂肪酸生物合成和累积相关的6个关键酶基因的表达模式与脂肪酸的合成和累积存在显著的相关性,基因家族的不同成员存在生物学功能的差异性和多样性。其中FAD2-3、FAD7、FATA、KAS2、LACS2、LACS8和SAD酶基因表达与脂肪酸总含量及主要脂肪酸含量呈显著正相关,说明7个酶基因表达对南美油藤种子油脂的合成与累积有促进作用;FAD2-2、KCS1、KCS10和LACS1酶基因与脂肪酸总含量及主要脂肪酸含量呈显著负相关,说明4个酶基因的表达对南美油藤种子油脂的合成与累积具有抑制作用。【结论】南美油藤种子成熟前后脂肪酸含量及差异表达基因存在显著差异,可依据种子中α-亚麻酸和亚油酸的含量变化将种子发育过程划分为脂肪酸缓慢累积和快速累积2个时期;南美油藤种子脂肪酸代谢中的6个关键酶基因的表达模式与脂肪酸的合成和累积存在显著的相关性,且同一基因家族的不同成员在脂肪酸的累积过程中可能具有不同的生物学功能。研究结果可为利用分子生物学技术提高南美油藤种子油产量和改变脂肪酸组分提供备选基因和相应的理论基础。     

Metabolomic Tools for Secondary Metabolite Discovery from Marine Microbial Symbionts

Marine invertebrate-associated symbiotic bacteria produce a plethora of novel secondary metabolites which may be structurally unique with interesting pharmacological properties. Selection of strains usually relies on literature searching, genetic screening and bioactivity results, often without considering the chemical novelty and abundance of secondary metabolites being produced by the microorganism until the time-consuming bioassay-guided isolation stages. To fast track the selection process, metabolomic tools were used to aid strain selection by investigating differences in the chemical profiles of 77 bacterial extracts isolated from cold water marine invertebrates from Orkney, Scotland using liquid chromatography-high resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance (NMR) spectroscopy. Following mass spectrometric analysis and dereplication using an Excel macro developed in-house, principal component analysis (PCA) was employed to differentiate the bacterial strains based on their chemical profiles. NMR ¹H and correlation spectroscopy (COSY) were also employed to obtain a chemical fingerprint of each bacterial strain and to confirm the presence of functional groups and spin systems. These results were then combined with taxonomic identification and bioassay screening data to identify three bacterial strains, namely Bacillus sp. 4117, Rhodococcus sp. ZS402 and Vibrio splendidus strain LGP32, to prioritize for scale-up based on their chemically interesting secondary metabolomes, established through dereplication and interesting bioactivities, determined from bioassay screening.