Novel biological floc, application thereof and method for nursing litopenaeus vannamei using novel biological floc

Abstract

The invention relates to a novel biological floc. The biological floc includes microalgae aggregates and commensalism heterotrophic bacteria, and the commensalism heterotrophic bacteria are Pesudomonas sp. and Bacillus sp. The biological floc significantly improves the water quality of the nursing pond of the litopenaeus vannamei, improves the survival rate, growth index and immunity of the litopenaeus vannamei, reduces the application amount of compound feed and external carbon sources, and reduces the aeration intensity and quantity of exchanged water.

Description

technical field [0001] The invention belongs to the technical field of agriculture, in particular to a novel biofloc and a method for applying and utilizing the same to standardize Litopenaeus vannamei. Background technique [0002] In 1999, Israeli scientist Avnimelech first proposed the application of Biofloc Technology (BFT) in the field of aquaculture. After nearly two decades of development, BFT has become a commonly used environmental regulation in aquaculture (especially crustacean farming). technology. The main point of the application of BFT is to adjust the C / N of the water body by artificially adding carbon sources, thereby promoting the formation of flocs in probiotics (such as bacillus, lactic acid bacteria, yeast, nitrifying bacteria, etc.), microalgae and protozoa in the water, and then Use floc biology to remove nitrogen, phosphorus, nutrients and excess organic matter in the water body, and convert them into bacteria / algae protein, and then become high-qual...

AI Technical Summary

Problems solved by technology

In recent years, with the improvement of farming scale and intensification, problems such as deterioration of water body environment, frequent occurrence of diseases, and degradation of germplasm resources have become prominent, seriously restricting the sustainable development of Litopenaeus vannamei farming industry

At present, although biofloc technology has been widely used in Litopenaeus vannamei culture, there are still a series of problems: 1. The core component of traditional biofloc is heterotrophic bacteria, and the C / N suitable for its growth and reproduction is at 10 Above, but the C / N of the general culture pond is about 4-5, which is far from meeting the growth needs of heterotrophic bacteria. Therefore, in practical applications, a large amount of carbon source substances must be added to the pond to promote the growth and reproduction of heterotrophic bacteria. If the amount is not properly controlled It will cause eutrophication of the water body and the breeding of pathogenic microorganisms, which will seriously deteriorate the water quality and endanger the normal life activities of prawns; 2. The number of photosynthetic and oxygen-evolving organisms such as microalgae in traditional bioflocs is very small, and the mass reproduction of heterotrophic bacteria will aggravate The dissolved oxygen load in the water body leads to the shortage of dissolved oxygen in the water body, and then affects the life activities of floc organisms through negative feedback, greatly weakening the environmental regulation and bait supplementation of bioflocs; 3. Bioflocs containing a large number of dead bacteria in the middle and late stages of breeding If it is not cleaned up in time, it will cause secondary pollution of the water body, and a large number of water changes will cause stress and stress on the shrimp, which will seriously affect the growth of the shrimp and even cause death. At the same time, the tail water produced by the farming will greatly increase the environmental load.

[0007] The bioflocs in this publication are mainly heterotrophic bacteria, and a large amount of carbon source substances are required to be added during the operation of the system. If the dosage is not well grasped, it will easily cause eutrophication of the water body, resulting in a large number of harmful microorganisms, and at the same time increase the dissolved oxygen load of the water body. To maintain the normal operation of the system requires continuous and high-intensity aeration, which pushes up the cost of farming

Litopenaeus vannamei juveniles prefer plant-based bait during the growth stage. In this technology, the biofloc mainly composed of bacteria can not achieve good bait concentration and food supplementation, and the amount of compound feed used in the breeding process of prawns is too large

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