高活性荚膜红假单胞菌分离鉴定及应用

[目的]分离筛选出高活性荚膜红假单胞菌,并作为水质净化剂和饲料添加剂应用于鱼苗生产培育中,以促进广西水产养殖业的健康发展.[方法]采用平板稀释涂布法从广西本地高产对虾塘底泥中分离筛选出活性较高的菌株,然后从形态学特征、生理生化特性及参照《伯杰氏细菌鉴定手册》等鉴定菌株,并将其应用于罗非鱼鱼苗培育试验.[结果]分离筛选出的光合细菌(菌株NC01)菌体卵圆形、革兰氏染色阴性,培养的菌落圆形、红色、边缘整齐、表面光滑、湿润,菌体大小0.6~0.9 μm×1.5~2.5 μm;在光照厌氧条件下培养,繁殖速度较快,在扩大培养基中培养液颜色由浅红色逐渐变成紫红色;根据《伯杰氏细菌鉴定手册》鉴定为荚膜红假单胞菌.将其应用于罗非鱼鱼苗生产培育,发现荚膜红假单胞菌能稳定水体pH,显著降低水体氨氮、亚硝酸盐、化学需氧量(COD)含量,降幅分别为36.69%、27.47%、45.89%;鱼苗体长增加43.66%、体重增加44.79%、成活率提高10.60%(绝对值).[结论]从广西本地高产对虾塘底泥中分离筛选出的荚膜红假单胞菌,其生理生化特性及商品性能良好,且在罗非鱼鱼苗培育中效果显著,生产上可以大批量生产并推广应用于水产养殖.

Identification and application of highly reactive Rhodopseudomonas capsulata

[Objective]Highly reactive Rhodopseudomonas capsulata was screened and used in fish fry production as water scavenger and feed addictive in order to promote the health development of Guangxi aquaculture.[Method]Highly reactive Rhodopseudomonas capsulata strains were isolated from Guangxi local highly-productive shrimp pond using dilution plating procedure,and their morphological,physiological and biochemical characteristics were identified.These strains were employed to the experiment of Tilapia mossambica fry cultivation.[Result]Separated photosynthetic bacteria(NC01) were gram negative,and showed round shape measuring about 0.6-0.9 × 1.5-2.5μm in diameter,red color,neat border,moist and shiny bacterial colony with smooth surface.Cultured under anaerobic illumination,the bacteria grew considerably faster in culture medium,gradually turning into fuchsia from light red.The bacteria,identified as Rhodopseudomonas capsulata according to Bergey’s Manual of Systemaic Bacteriology,were used to culture Tilapia mossambica fry.The results showed that Rhodopseudomonas capsulata could stabilize pH value of water,significantly decrease the content of ammonia nitrogen,nitrite and COD by 36.69,27.47% and 45.89%,respectively;further,body length,body weight and survival rate of fry increased by 43.66,44.79 and 10.60%(absolute value),respectively.[Conclusion]Rhodopseudomonas capsulata(NC01),isolated from Guangxi local highly-productive pond,shall be extended in aquaculture practices due to its good physiological and biochemical characteristics,fine commodity functions and effective Tilapia mossambica fry culture.