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991.
Woo-Ri Kang Min-Ju Seo Jung-Ung An Kyung-Chul Shin Deok-Kun Oh 《Biotechnology letters》2016,38(5):817-823
Objective
To produce δ-decalactone from linoleic acid by one-pot reaction using linoleate 13-hydratase with supplementation with whole Yarrowia lipolytica cells.Results
Whole Y. lipolytica cells at 25 g l?1 produced1.9 g l?1 δ-decalactone from 7.5 g 13-hydroxy-9(Z)-octadecenoic acid l?1 at pH 7.5 and 30 °C for 21 h. Linoleate 13-hydratase from Lactobacillus acidophilus at 3.5 g l?1 with supplementation with 25 g Y. lipolytica cells l?1 in one pot at 3 h produced 1.9 g l?1 δ-decalactone from 10 g linoleic acid l?1 via 13-hydroxy-9(Z)-octadecenoic acid intermediate at pH 7.5 and 30°C after 18 h, with a molar conversion yield of 31 % and productivity of 106 mg l?1 h?1.Conclusion
To the best of our knowledge, this is the first production of δ-decalactone using unsaturated fatty acid.992.
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996.
Fish samples for the study were collected from the Yangtze River in China. Length–weight relationships were determined for two endemic fish species (Leiocassis longirostris Günther, 1864 and Schistura fasciolata Nichols & Pope, 1927) for the first time. 相似文献
997.
Measuring fish length and assessing behaviour in a high‐biodiversity reach of the Upper Yangtze River using an acoustic camera and echo sounder 下载免费PDF全文
In the past decade improved acoustic hard‐ and software have enabled estimations of abundance and distribution patterns of aquatic organism, including non‐intrusive monitoring of fish migrations and behaviour. In this study, a high frequency acoustic camera (DIDSON‐LR, 1.2 MHz, 0.7 MHz) and a portable split‐beam scientific echo sounder (Simrad EY60, 200 kHz) collected acoustic data on 192 and 157 individuals within 24 hr (19–20 April 2011) in the Mituo reach of the Yangtze River, China. Mean fish length estimated from the acoustic camera data was 18.7 ± 5.6 cm, with an average swimming speed of 0.19 ± 0.13 m s?1. The mean fish target strength (TS) produced by the echo sounder was ?43.8 ± 4.4 dB, which corresponded to 5.7–119.9 cm fish length when converted by three different TS‐length equations. Average swimming speed was 0.11 ± 0.06 m s?1 from the echo sounder. Compared with the actual fish catch by the three layers of drift gill net in the survey area, the target length indicated by DIDSON was more accurate than the EY60 results, which were highly affected by the choice of TS length equations. It was determined that the two devices used synchronously could estimate fish length effectively to investigate their behaviour and distribution. 相似文献
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Effect of dietary L‐malic acid supplementation on growth,feed utilization and digestive function of juvenile GIFT tilapia Oreochromis niloticus (Linnaeus, 1758) 下载免费PDF全文
Y.‐J. Chen L. Luo G.‐Z. Zhang Z. Li F.‐J. Bai Y.‐Q. Shi H.‐S. Yang 《Zeitschrift fur angewandte Ichthyologie》2016,32(6):1118-1123
Two feeding trials (FTs) were conducted in 2013 and 2014, respectively, to determine the optimal L‐malic acid (LMA) level for juvenile GIFT (Genetically Improved Farmed Tilapia) Oreochromis niloticus. Except for the LMA level, the FT1 and FT2 had a similar diet formulation. In FT1, LMA was included at 0 (basal diet), 1, 4, 8, 16 and 32 g kg?1, respectively. After 20 weeks, daily weight gain and feed conversion ratio were improved but not differentiated with 1–8 g kg?1 LMA. Further increasing the LMA supply initially decreased the feed intake (16 g kg?1), and then decreased both feed intake and feed utilization (32 g kg?1), thus impairing the fish growth. FT2 was subsequently conducted with a smaller LMA range (0, 0.5, 1, 2, 4 and 8 g kg?1, respectively) but was unfortunately terminated at the end of 8 weeks because 20% of the fish were badly injured during weighing. Unexpectedly, growth and feed utilization were still improved but not differentiated with 0.5–8 g kg?1 LMA. In FT2, beneficial effects of LMA inclusion on the digestive function (pepsin, foregut amylase and foregut lipase), the activities of serum lysozyme and hepatic superoxide dismutase, and liver lipid peroxidation (malondialdehyde concentration) were found. Taking the results of FT1 and FT2 together, it could be concluded that dietary LMA supplementation at low concentrations (0.5–8 g kg?1) could improve growth and feed utilization, but excess LMA (≥16 g kg?1) might compromise feed intake and/or feed utilization, thus impairing fish growth. To reduce feed costs in commercial practice, 0.5 g kg?1 LMA is recommended in the feed of juvenile GIFT tilapia based on the results of this study. 相似文献
1000.
Length–weight relationships for four fish species upstream in the Minjiang River,southeastern China 下载免费PDF全文
M. F. He D. Q. Yuan W. Xiong Y. F. Chen 《Zeitschrift fur angewandte Ichthyologie》2016,32(6):1316-1317
Length–weight relationships were determined for four fish species (Hemibarbus labeo Pallas, 1776; Tachysurus nitidus Sauvage & Dabry de Thiersant, 1874; Pseudobagrus vachelli Richardson, 1846; Glossogobius olivaceus Temminck & Schlegel, 1845) upstream in the Minjiang River in Fujian Province, southeastern China. Samples were collected employing various fishing gear in 2012–2013. The present report is the first record of the length–weight relationships for these species. 相似文献