葡萄糖对对虾养殖水体水质的影响

研究葡萄糖的不同添加量(1.25~5×10-3 g/L)对对虾养殖水体水质指标(氨氮、活性磷)和微生物数量(总异养菌、弧菌)的影响。结果显示,与对照组相比,水体中添加葡萄糖能明显提高异养菌、弧菌密度(P<0.05),显著降低养殖水体中氨氮、活性磷浓度(P<0.05)。且在一定浓度范围内,葡萄糖浓度越高,氨氮、活性磷浓度越低,异养菌、弧菌密度越高。     

头孢氨苄对斑节对虾幼体发育及育苗水体细菌数量的影响

研究了不同浓度头孢氨苄(Cefalexin)对斑节对虾Penaeusmonodon幼体发育以及对斑节对虾育苗水体中异养菌总数和弧菌数量的影响。在试验初期,无论是对照组还是施用头孢氨苄的各试验组,育苗水体中的总异养菌数量和弧菌数量都呈现出较为明显的上升趋势;在第二次施用头孢氨苄后,各试验组的异养菌总数和弧菌数量的增幅明显低于对照组(或出现异养菌总数和弧菌数量缓慢下降),而对照组异养菌总数和弧菌数量则呈现显著的上升。施用0.5～1.0μL·L-1头孢氨苄对育苗水体中的总异养菌有显著的杀灭及抑制作用,但对弧菌数量杀灭及抑制作用并不显著;施用1.5μL·L-1头孢氨苄对育苗水体中的总异养菌和弧菌数量的杀灭及抑制作用显著。当幼体变态发育至仔虾第8天(P8)时,对照组异养菌总数和弧菌数量分别达6.33×105和3.55×104CFU·mL-1,均远远高于试验组的异养菌总数和弧菌数量增长的幅度。试验组的幼体变态到P1期的时间,比对照组缩短了10h以上;试验组的成苗率也比对照组提高了3.2%～13.1%。     

产乳酸芽孢杆菌对对虾养殖水体水质的影响

在温度(28±1)℃、盐度28下,将产乳酸芽孢杆菌制剂添加到养殖10尾凡纳滨对虾、容水200L的0.3m~3室内玻璃钢桶中,使芽孢杆菌终密度为10~4、10~5、10~6 cfu/mL,以无益生菌添加组为对照组。定期测定养殖水体中的氨氮、亚硝酸盐氮和硝酸盐氮的含量,以及总异养菌、弧菌和芽孢杆菌的数量。试验结果显示,试验结束时,添加芽孢杆菌各试验组养殖水体中氨氮、亚硝酸盐氮和弧菌的含量显著低于对照组(P0.05);添加高密度芽孢杆菌试验组(10~6 cfu/mL)养殖水体中总异养菌的数量显著高于对照组(P0.05);添加芽孢杆菌对养殖水体中的硝酸盐氮含量未产生显著的影响(P0.05);添加芽孢杆菌后养殖水体中的芽孢杆菌数量在第4d后会出现下降趋势。试验还发现,在养殖后期初次投入芽孢杆菌时会引起养殖水体中氨氮含量的短期升高。试验结果表明,芽孢杆菌能改善对虾养殖水体水质,可作为益生菌用于对虾养殖中。     

斑节对虾双季养成期间虾池水质和底泥细菌含量的变化

本文报导了斑节对虾双季人工淡化养殖,虾池水与底泥异养菌和弧菌的数量变化及其与主要理化环境因子的关系。表明上半年的第一茬养殖虾池无论是水或底泥的异养菌数和弧菌总数均容易调控在低数量水平,第二茬养殖由于高水温持续整个养殖周期,诸多环境因子波动较大,在人工管理调节下,虾池主要环境因子(细菌数、化学耗氧量、氨氮、溶解氧、pH值)仍处在正常的范围内,但是却显示不出它们之间的相关性,在两茬的养殖中底泥异养菌数和弧菌数都分别比水中高两个数量级和一个数量级。     

斑节对虾养殖池塘藻-菌关系初探

本研究通过对斑节对虾养殖系统中的异养细菌、浮游微藻进行为期3个月的监测，发现浮游微藻和异养细菌的总量都表现为养殖后期高于养殖前期，其中浮游微藻增加了2个数量级，异养细菌增加了1个数量级，施放有益芽孢杆菌群对池塘菌群和藻群的变动有明显的影响。施放有益芽孢杆菌群的池塘，异养细菌总数略低，弧菌数量维持在10^3 CFU／mL以下，浮游微藻平稳增长，蓝藻占20％以下；对照池异养细菌的总数略高，弧菌数量达到10^3 CFU／mL，浮游微藻数量波动，养殖后期蓝藻占60％，为绝对优势种群。表明有益芽孢杆菌群有促进浮游微藻平稳繁殖的作用，但对浮游蓝藻和弧菌的繁殖起抑制作用，浮游蓝藻与弧菌之间具有一定的繁殖相关性。     

微生态制剂对中国对虾养殖池塘底质改良效果的探讨

以中国对虾为养殖对象,通过在其养殖环境中施加不同浓度复合微生态制剂进行池塘底质的检测和分析,探讨了复合微生态制剂对养殖池塘底质改良作用。试验选用了4个池塘,经60d的养殖,结果表明,在相同的外界环境条件下,各处理池塘底质中有机质和总碳含量低于对照组,高浓度的微生态制剂组施加量有更好的效果。通过检测底质中异养菌和弧菌数量表明,复合微生态制剂可以降低池塘底质中异养菌和弧菌的数量,有效抑制有害菌的生长。     

军曹鱼肠道及水体异养菌和弧菌的周年变化

采用总活异养菌2216E平板计数法和弧菌TCBS平板计数法对广东深圳大鹏养殖军曹鱼(Rachycentron canadum Linnaeus)养殖水体及鱼肠道细菌进行了周年监测。结果显示,育苗初期养殖水体异养菌和弧菌密度分别为0.63×104～6.2×104CFU/mL和0.30×102～1.03×104CFU/mL,鱼肠道异养菌和弧菌密度分别为0.80×106～7.5×107CFU/g和0～1.30×107CFU/g;网箱养殖监测期间,养殖水体异养菌和弧菌密度分别为4.20×103～5.40×105CFU/mL和0.70×102～1.14×105CFU/mL,鱼肠道异养菌和弧菌密度分别为1.50×107～8.78×108CFU/g和1.00×107～3.50×108CFU/g。周年监测结果显示,水体异养菌、弧菌的数量高峰均出现于8-9月份;肠道异养菌及弧菌的数量高峰均出现于6-7月份,分别又在12月份和2月份出现次高峰,弧菌变化趋势始终与异养菌一致。对分离得到的407株菌鉴定到属并进行多样性分析。结果显示,育苗期水体以假单胞菌(Pseudomonas)、黄单胞菌(Xanthomonas)和芽孢杆菌(Bacillus)为优势菌,三者约占水体异养菌总数的70%;养殖后期,弧菌(Vibrio)和发光杆菌(Photobacterium)的数量逐渐上升并占据一定优势,其中假单胞菌、黄单胞菌、弧菌和芽孢杆菌常年出现。鱼肠道异养菌以假单胞菌和芽孢杆菌为优势菌,其次是肠杆菌科(Enterbacteriaceae)细菌,也多次检测到弧菌、发光杆菌、气单胞菌(Aeromonas)和小球菌(Microccus)等。总之,养殖微生态系统的可持续稳定平衡与系统的种群多样性、群落组成及水质因子等因素相关,而整个环境生态系统的平衡直接影响到鱼类肠道的细菌生态系统。     

凡纳滨对虾(Litopenaeus vannamei)低盐度围隔调控养殖环境微生物研究

在广东省珠海市斗门一个大小为0.3hm2的空白虾池内,设立10个大小为5×5×1.6m(l×b×d)的陆基池塘围隔,对凡纳滨对虾低盐度调控养殖环境微生物进行实验研究,结果低盐度围隔调控养殖系统,水体异养细菌平均为1.33~9.27×104cfu.ml-1,致病性弧菌平均为2.83~7.91×102cfu.ml-1,养殖水体致病性弧菌的数量比异养细菌平均低2个数量级。各围隔水体异养菌在养殖早期都有一个高峰期,中后期低而稳定;围隔异养细菌的数量并未因定期施菌而增高,反而呈下降的趋势。对虾养殖健康的围隔,中后期水体致病性弧菌保持较低的数量,而对虾发病的围隔,致病性弧菌数量高。围隔调控养殖系统,异养细菌的数量相对比较稳定,而致病性弧菌数量呈较大波动。     

中国对虾（Penaeus chinensis）养成期虾池水体和底质及虾体异养菌…

本文报道了辽宁省瓦房店市邓屯乡高家养虾场对虾养成期虾池水体和底层及虾体异养菌和弧菌含量的变化，结果表明外海水中异养菌数量的１０＾４～１０＾５个／毫升，弧菌数量为１０＾２～１０＾３个／毫升，虾池水中异养菌数量为１０＾４～１０＾５个／毫升，弧菌数量为１０＾２～１０＾４个／毫升，底质中异养菌数量为１０＾５～１０＾７个／克，弧菌数量为１０＾３～１０＾４个／克。虾体肌肉中异养菌数量为１０＾３～１０＾５个／克     

光合细菌在虾病防治中的作用研究

本文着重研究光合细菌(PSB)在虾病防治中的作用,结果表明:对虾养殖池施用光合细菌后,随PSB浓度的增加水质、底泥中弧菌和异养细菌数量而逐渐减少,表明了PSB具有调节和改善养殖的微生态环境的作用。PSB还能降低底泥中的有机质和硫化物含量,降低COD含量,并提高养殖水体的溶解氧,改善水生环境。本文还分析了PSB在长毛对虾幼体培育中的应用效果,光合细菌的营养通过食物链的传递,促进对虾生长,增强对虾抗病能力,降低发病率和死亡率。     

强天气干扰条件下粤西凡纳滨对虾养殖池塘细菌群落动态特征

于暴雨频发的华南雨季（2009年5月-8月）对粤西凡纳滨对虾（Litopenaeus vannamei）养殖池塘水体和底泥进行调查,研究在强天气干扰条件下养殖池塘细菌数量动态及多样性指数变化情况。结果发现,水体异养细菌在104-106 cfu？mL-1间波动,弧菌数量在养殖初期高达105 cfu？mL-1, 虾池301# 和404# 自6月18日开始施用芽孢杆菌（Bacillus subtilis）等微生态制剂后,其弧菌（Vibrio sp.）数量维持在104 cfu？mL-1以下,403# 和305# 波动较大且多次超过105 cfu？mL-1;4口虾池水体弧菌与异养细菌的数量比值在养殖初期均超过20%,之后301# 和404# 保持在12%以下,403#和305# 在养殖后期分别达到21%和33%。底泥异养细菌先升高后稳定,弧菌数量除305# 较稳定外,其他虾池波动较大（103-107 cfu？g-1）。施用微生态制剂池塘301#和404#水体微生物群落多样性较前期降低,305#和403#较前期升高;底泥微生物群落多样性则呈现相同的变化规律,群落的丰富度、常见种的优势度和群落均度较前期有所降低。结果表明,施用微生态制剂的虾池可在气候多变的情况下保持养殖水体细菌群落的相对稳定,抑制弧菌滋生,降低微生态环境风险。     

光合细菌对三角帆蚌养殖水体水质的影响

将红螺菌科的红假单胞菌应用于三角帆蚌(Hyriopsis cum ingii)养殖水体,测定水化学环境因子和微生态群变化情况。结果表明,光合细菌可稳定养殖水体pH,去除氨氮、亚硝基氮、总氮,降低COD,改变水体氮磷比;光合细菌能有效控制异养细菌、弧菌、气单胞菌数量,对真菌的增殖也有一定抑制作用,避免养殖水体水质恶化。     

Relative Abundance and Species Composition of Gram-Negative, Aerobic Bacteria Associated with the Gut of Juvenile White Shrimp Litopenaeus vannamei Reared in Oligotrophic Well Water and Eutrophic Pond Water

Gut bacteria may contribute significantly to the growth and survival of cultured shrimp, although little is known about factors that affect bacterial community structure in shrimp guts. The objective of this study was to determine the abundance and species composition of gut bacteria in juvenile white shrimp Litopenaeus vannamei reared in two different environments. Eight 120-L tanks were stocked at a density of 8 shrimphank. Two treatments were tested for 10 d and consisted of tanks receiving flow-through water from one of two sources: 1) well water pumped from a sea-water aquifer (Well treatment), and 2) pond water pumped from an intensive shrimp pond (Pond treatment). Shrimp mid- and hindguts were excised on days 1, 3, 6, and 10 for enumeration of gram-negative, aerobic bacteria by quantifying colony-forming units (CFU) using standard microbiological plating techniques. Identification of bacterial isolates was made using the Biologa® GN Microplate system. Bacterial numbers were significantly greater ( P > 0.05) in Well shrimp than in Pond shrimp on days 1 and 3. Following day 3, a decrease in bacterial numbers occurred in the Well shrimp, and no significant differences between treatments were observed on days 6 or 10. Guts from Well shrimp were dominated by Vibrio and Aero-monas , and these two genera accounted for 80–851 of the bacteria on each sampling day. Guts from Pond shrimp exhibited a greater bacterial diversity and were dominated by Vibrio, Aeromonas , and Pseudomonas. Flavobacterium were identified in the guts of Pond shrimp on days 3 and 10, but were not identified in any of the Well shrimp. A greater understanding of gut bacteria-shrimp interactions could lead to increased production and profitability for shrimp farmers through the development of more cost-effective feeds and novel disease control strategies.     

草鱼养殖水体中参与氮转化途径的异养菌分析

为分析草鱼池塘中参与氮代谢的异养细菌比例及其代谢途径,从杭州郊区取得4个草鱼池塘的水样,每个水样通过涂布随即挑选100株菌株进行定性显色试验,并据此选取11株异养菌进行16S rRNA序列分析。结果表明,4个草鱼养殖池塘中NH4+-N和NO2--N的平均水平分别为5.597 mg/L和0.135 mg/L。池塘中可培养的异养菌平均为3.26×105cfu/mL,其中的89.75%参与了氮的不同代谢途径,其中31.25%的氨化菌和33.50%NO3--N(NO2--N)还原菌参与了NH4+-N的生成,32.45%的氨氧化菌参与了NH4+-N的降低;NO2--N生成途径主要包括蛋白质直接转化(11.26%)、氨氧化(4.25%)和硝酸盐氮还原(10.75%),而NO2--N降低主要通过15.50%的亚硝酸氧化菌、8.75%的NO2--N还原菌和10.75%的反硝化菌实现。结果提示,草鱼养殖水体中存在大量的异养硝化菌参与不同的氮代谢途径,且产生氨氮的异养菌比例远高于去除氨氮的菌,这是草鱼养殖水体中氨氮含量易偏高的原因。同时,11株不同功能的异养菌16SrRNA鉴定结果为寡养食单胞菌(Stenotrophomonas)6株、假单胞菌(Pseudomonas)3株、克雷伯氏菌(Klebsiella)和肠杆菌(Enterobacter)各1株,而且细菌对氮源的利用具有菌株特异性。     

刺参苗期附着基更换频率对刺参生长及其养殖系统菌群结构的影响

为了探究刺参(Apoasichopus japonicus)保苗阶段(7–9月)最佳的附着基更换频率(changing frequency,CF),本实验在夏季保苗期设置5个附着基更换频率组,即CF10、CF20、CF_(30)、CF40和CF_(50)。采用实验生态学的方法,并结合传统细菌培养法和16S r DNA细菌鉴定技术对上述不同实验组进行检测。结果表明:CF20组刺参整池增重和个体增重幅度最大,CF_(30)次之,CF_(50)组由于死亡率高,整池重量为负增长。CF20组的特定生长率和存活率分别为(5.986±0.135)%/d和(95.231±0.265)/%,且显著高于其他各组(P0.05),CF_(30)次之,而CF_(50)组的特定生长率和存活率最低,且显著低于其他各组(P0.05)。养殖用水中4NH+-N、2NO--N和COD随着附着基更换频率的降低而升高,并在第50天时分别达到0.53 mg/L、0.28 mg/L、0.18 mg/L。各实验组水体中异养细菌和弧菌数量随附着基更换频率变化不明显,而附着基上的异养细菌和弧菌数量随附着基更换频率的降低而升高,CF_(50)组异养细菌总数在第50天时达到1.38×105 cfu/cm2,弧菌数量达到1.5×104 cfu/cm2,皆明显高于其他各组。附着基上优势菌为溶藻弧菌(Vibrio algindyticus)、需钠弧菌(V.natriegens)、马胃葡萄球菌(Staphylococcus equorum)、枯草芽孢杆菌(Bacillus subtilis)、苏云金芽孢杆菌(B.thuringiensis)和副溶血弧菌(V.parahaemolyticus)。其中,溶藻弧菌为刺参条件致病菌,且一直存在于养殖系统中并逐步占据绝对优势。这与CF_(50)组在实验进行到43 d时开始出现化皮,50 d时开始出现死亡现象有一定的关系。同时,附着基长时间未更换,会滋生大量玻璃海鞘、日本毛壶、内刺盘管虫等敌害生物,争夺栖息空间和食物,导致刺参苗种生长减慢。综上,由实验结果显示,在7–9月高温季节每20 d更换一次附着基最佳。考虑到生产成本,附着基更换频率一般为20~30 d为宜。本研究结果为刺参苗种培育工艺的优化及刺参健康养殖提供了理论依据和参考。     

Temporal fluctuation in the abundance of alginate‐degrading bacteria in the gut of abalone Haliotis gigantea over 1 year

In this study, we identified and enumerated alginate‐degrading bacteria in the gut of abalone over 1‐year period. From a total of 360 colonies growing on agar medium enriched with alginate, 251 isolates (70%) had the ability to degrade alginate. In addition, a high number of viable alginate‐degrading bacteria were detected throughout the survey period. Alginate‐degrading bacteria were more abundant in the cold season relative to the summer season (10⁷ vs. 10⁴ CFU g^?1, respectively). Strong positive correlation was also observed between the number of alginate‐degrading bacteria and feed intake (R = 0.854; P < 0.01). The identified alginate‐degrading bacteria comprised of 35 species grouped into 11 genera including Algibacter, Formosa, Polarybacter, Tamlana, Tenacibaculum (CFB group), Roseobacter, Ruegeria, Silicibacter (α‐proteobacteria), Agarivorans, Shewanella and Vibrio (γ‐proteobacteria) respectively. More than 80% of the isolated alginate‐degrading bacteria belonged to the genus Vibrio, showing high homology to Vibrio cyclotorophicus, Vibrio splendidus, Vibrio halioticoli and Vibrio neonatus. Based on the results, it was suggested that algal‐polysaccharide (alginate) degrading bacteria (mainly Vibrio) commonly exist in the gut of abalone and may play an important role in the degradation and digestion of the host's feed.     

Bacteria associated with early life stages of halibut, Hippoglossus hippoglossus L., inhibit growth of a pathogenic Vibrio sp.

Abstract Bacteria capable of inhibiting growth of a pathogenic Vibrio sp. were isolated from the gastrointestinal tract of cultured halibut larvae during the first feeding and weaning stages. No such bacteria were found among isolates from the surface of eggs or the gastrointestinal tract of yolk sac larvae. The fraction of pathogen-inhibitors among the total number of isolates ranged between 0–100% (first feeding) and 0–66% (weaning). All pathogen-inhibitors were Gram-negative rods, and 95% were oxidase and catalase positive fermentative isolates, capable of producing acid aerobically from a varying range of carbohydrates. These isolates possessed the characteristics of the Vibrio/Aeromonas -group, but only 19% were sensitive to the vibriostatic agent 0/129. Isolates from eggs and yolk sac larvae were dominated by bacteria belonging to the Cytophaga/Flexibacter/Flavobacterium - group. The high fraction of isolates with the ability to inhibit growth of the pathogenic Vibrio sp. among the total number of isolates indicates that pathogen inhibition may be an important mutualistic role of the intestinal flora of early life stages of halibut.     

Heterotrophic versus mixed BFT system: Impacts on water use,suspended solids production and growth performance of Litopenaeus vannamei

The Biofloc Technology System (BFT) is characterized by stimulating the development of a microbial community that acts mainly in the maintenance of water quality but also promotes other benefits such as increased productivity, biosafety and serves as a supplementary source of food for reared animals. Two main groups of bacteria are involved in nitrogen removal in this system: heterotrophic bacteria and autotrophic nitrifying bacteria, present in the aggregates. Different fertilization techniques can be used for the formation and maintenance of bioflocs, depending on which group of bacteria the predominance is preferred. This study aimed to analyze the effect of different organic fertilization techniques on the bioflocs establishment, amount of water used, the production of suspended solids and the growth performance of Litopenaeus vannamei reared in the BFT System. Shrimp juveniles were stocked in 150-liter tanks at a stocking density of 300 shrimps/m³. Three treatments (in triplicate) were tested using different fertilization techniques: 1) without supplementary organic fertilization; 2) organic fertilization according to nominal ammonia reading (heterotrophic/chemoautotrophic = “mixed” system) and 3) organic fertilization according to estimated ammonia production (heterotrophic). The temperature, salinity, dissolved oxygen, pH, ammonia, nitrite, nitrate, alkalinity and total suspended solids (TSS) of the water were monitored. The water quality parameters were influenced by the treatments with differences found in the concentrations of ammonia, nitrite, nitrate, pH, alkalinity and TSS. Ammonia levels were higher in control treatment since no organic fertilization was performed. Nitrite levels were lower in heterotrophic system since the nitrifying pathway was suppressed due to daily fertilization, also resulting in lower nitrate levels. There were significant differences in the growth performance parameters, with the highest final weight and yield, as well as the lowest FCR, found in the mixed treatment. There were no significant differences among survival. The mixed system treatment used less water during production cycle compared to other treatments while the volume of solids removed was almost four times greater in the heterotrophic treatment compared to the others. These results show that adopting a mixed heterotrophic/chemoautotrophic biofloc system improves shrimp growth performance, optimize water use and decrease solids production.     

饲料中补充蜡样芽孢杆菌(Bacillus cereus)生物膜对凡纳滨对虾(Litopenaeus vannamei)生长、抗病力及其肠道微生物组成的影响

为了研究外源补充蜡样芽孢杆菌(Bacillus cereus)生物膜对凡纳滨对虾(Litopenaeus vannamei)生长、抗病力及对其肠道微生物组成的影响,以基础饲料为空白组,在基础饲料中添加蜡样芽孢杆菌游离态活菌作为游离态组(活菌含量为108 CFU/g);在基础饲料中添加蜡样芽孢杆菌活菌生物膜作为生物膜组(活菌含量为108 CFU/g);每组8个平行.在养殖大棚暂养7d后,对凡纳滨对虾进行40 d的养殖实验.在第17天进行白斑综合征(White Spot Syndrome Virus,WSSV)攻毒实验;第22天进行副溶血弧菌(Vibrio parahaemolyticus)攻毒实验.期间在第1、5、10、15天采样,称重并测量体长计算生长速率.在第1、5、10、15、20、25天采样,并取其肠道内容物提取DNA,用16S rDNA序列V3+V4区高通量测序方法检测对虾肠道内微生物群落的结构及变化情况.结果显示,生物膜组和游离态组对虾体重、体长增长速率高于空白组,生物膜组与游离态组对虾体重、体长差异性不显著,生物膜组和游离态组对虾体重、体长与空白组相比差异性显著.实验中凡纳滨对虾肠道微生物由变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)等组成,其中,变形菌门平均占到总量的94.0％.变形菌门中主要以弧菌属(Vibrio)、发光杆菌属(Photobacterium)、Octadecabacter等为主,生物膜组、游离态组、空白对照组弧菌属平均含量分别为34.65％、39.27％、58.00％.在WSSV攻毒实验中,生物膜组、游离态组、空白对照组平均累积死亡率分别为80.0％、77.0％、92.0％,各组差异性不显著(p＞0.05).在副溶血弧菌攻毒实验中,生物膜组、游离态组、空白对照组平均累积死亡率分别为61.3％、75.0％、77.3％,生物膜组与游离态组和空白对照组相比差异性显著(P＜0.05).研究表明,饲料中添加蜡样芽孢杆菌生物膜和游离态蜡样芽孢杆菌投喂凡纳滨对虾后,可改变对虾肠道的微生物组成,提高凡纳滨对虾生长速度、增强抗病能力,而且添加蜡样芽孢杆菌生物膜效果最明显.     

Effects of a yeast‐based additive on growth and immune responses of white shrimp,Litopenaeus vannamei (Boone, 1931), and aquaculture environment

A 60 days feeding experiment was conducted to determine the effects of YK‐6 (a yeast culture feed supplement) on growth and immune responses of white shrimp, Litopenaeus vannamei and aquaculture environment in commercial scale farms composed of nine ponds. Three treatments (control, Diet 1 and Diet 2) were designed to contain YK‐6 levels of 0.0, 1.0 and 1.5 g kg^?1 respectively. At the end of the test, the mean production of Diet 1 (0.649 ± 0.030 kg m^?2) and Diet 2 (0.648 ± 0.033 kg m^?2) were significantly higher than that of the control by 29.5% and 29.3% respectively. The feed conversion ratio decreased significantly by 12.3% (Diet 1) and 8.5% (Diet 2) compared with the control group respectively. The environmental indices indicate that the quality of water and pond sediment was improved. The endotoxin concentrations, the number of Vibrios and heterotrophic bacteria in the shrimp intestine of the treatment groups were significantly lower than that of the control, particularly in the later stage of the farming period. The YK‐6 extended positive effects on growth, improved sediment quality, reduced endotoxin in shrimp intestine, and enhanced activities of lysozyme and phenoloxidase.