NOVELTY - Bacteria are prepared by using modern biological engineering technology aiming in physical and ecological characteristics of holothurians and characteristics of water quality and substrate for holothurians (sea cucumber) culturing pools. A dozen of bacterial strains including photosynthetic bacteria, Bacillus, microenzyme, and ray fungi are used as main sources, which are domesticated, rejuvenated, and cultured. The microbe groups have intergrowth and multiplication relationship during their individual growing process.    USE - Preparation of bacteria for preserving holothurians.    ADVANTAGE - The method provides bacteria that are stable and easy to preserve for a long time; can quickly recover and disintegrate once they are in water; can become superior species group through multi-reproduction; degrade speedily organic pollutants in water; eliminate harmful substances like amino nitrogen, nitrosonitrogen, and hydrogen sulfide and convert them into nutrient source for oceanic unicellular algae; promote growth of beneficial algae while restraining reproduction of harmful ones; and nurture and improve the water quality and increase transparency of water body and oxygen dissolution for substrate purification.    DETAILED DESCRIPTION - Preparation of bacteria comprises using modern biological engineering technology aiming in physical and ecological characteristics of holothurians and characteristics of water quality and substrate for holothurians culturing pools. A dozen of bacterial strains including photosynthetic bacteria, Bacillus, microenzyme, and ray fungi are used as main sources, which are domesticated, rejuvenated, and cultured respectively. The microbe groups have an intergrowth and multiplication relationship during their individual growing process. They are selectively paired with bacteria structure and adopt unique fermenting and concentrating techniques. The preparation of bacteria for preserving holothurians adopts the vacuum processing, low temperature, quick freezing, drying, and concentrating. The micro ecological preparation involves:    (A) dissolving PS positive ion gel starch in water, diluting 10 times to obtain 10% solution, and sterilizing;    (B) adding the dissolved solution into cultured EM bacterial fluid, stirring until thalli flocculate generates in the bacteria fluid, and removing water to obtain thalli cells;    (C) adding ultra-concentrated EM thalli cells into dried powder sea mud, and stirring;    (D) sieving microenzyme powder, potassium nitrate powder, sodium silicate powder, sodium ethylene diamine tetracetate powder, iron citrate powder, and monosodium orthophosphate powder using 60 screen mesh; and    (E) blending the sieved powders at a proportion of 30:10:30:22:2:3:3.