Produce 02 preparations of liquid paste purple non sulfur bacteria for food bivalve animal breeds and treatment environment for aquaculture.

Theoretical results:
- A suitable medium for biomass accumulation and protein synthesis was selected for the mixture of purple non sulfur bacteria used as feed for bivalves breed animals containing 1.4 g/l Glutamate and 0.6 g/l Malate.
- An in expensive, easy-to-find substrate source for the cultivation of purple non sulfur bacteria to treat sulfides and organic compounds on pilot scale has been selected including soybean meal 1 g/l, acetate 0.5 g/l and 10 mg Mg2+, when grown on this medium, the sulfide treatment efficiency reached 100% with the initial sulfide concentration of 10 mg/l.
- Chitosan has been selected for precipitating of purple non sulfur bacteria biomass to create liquid paste products with an optimal concentration of 150 mg/l in 30 minutes.
- Created liquid paste products with carrageenan concentration of 0.6%.
- Selected to conditions preserve the liquid paste products for food of bivalves breed animal’s treatment of sulfide and organic compounds to store at room temperature and 4 - 10oC. These two conditions were testing the addition of preservatives.
- Selected 1% concentration sodium erythorbate (E316) stored at room temperature to maintain high density and dark purple color, nutritional value and sulfide removal activity after 6-12 months of storage. The product is better to store under the light than in the dark.
- Successfully built a process to produce a liquid paste of purple non sulfur bacteria that can be applied for the treatment aquaculture ponds and as food for bivalves breed animals reaching 1-5 kg/batch.
- Experimented using liquid paste purple non sulfur bacteria as feed for bivalves breed animals at the scale of 1000 m2/pond, repeating 3 times for experiments for high survival rate of clam larvae. The survival rate of clam larvae when fed with liquid paste purple non sulfur bacteria which compared with fed with algae and commercial feed were not statistically significant differences.
- Using liquid paste of purple non sulfur bacteria products to treat shrimp pond water at the scale of 1000 m2/ pond in comparation with control ponds treated with Yucca Zeo and EM1 were not statistically significant different. The obtained results showed that the experimental ponds treated with VKTQH liquid paste of purple non sulfur bacteria product did not have a statistically significant different in shrimp growth.
Applied results:
- Successfully built a process to produce a liquid paste of purple non sulfur bacteria that can be applied for the treatment aquaculture ponds and as food for bivalves breed animals reaching 1-5 kg/batch.
-Two liquid pastes of purple non sulfur bacteria products have been created as food for bivalve breed animals and for the treatment of aquatic environment those are easy to use and transport to aquaculture areas throughout the country.
- Experimented using liquid paste purple non sulfur bacteria as feed for bivalves breed animals at the scale of 1000 m2/pond, repeating 3 times for high survival rate of clam larvae. The survival rate comparing of clam larvae when fed with liquid paste purple non sulfur bacteria which compared with clam fed with algae and commercial feed were not statistically significant different.
- Using liquid paste of purple non sulfur bacteria products to treat shrimp pond water at the scale of 1000 m2/ pond in comparation with control ponds treated with Yucca Zeo and EM1 were not statistically significant difference. The obtained results showed that the experimental ponds treated with VKTQH liquid paste of purple non sulfur bacteria product did not have a statistically significant difference in shrimp growth.

The first time in Vietnam, the liquid paste products of purple non sulfur bacteria have been created for food of bivalves breed animals and sulfide, organic compounds treatment  which have been confirmed with positive results. Liquid paste products of purple non sulfur bacteria products in liquid form are highly concentrated, easy to use and transport to aquaculture areas.

- Patents (list): Do Thi Lien, Do Thi To Uyen, Cung Thi Ngoc Mai, Lê Thi Nhi Cong. The pure purple photosynthetic bacterium Rhodobacter sp. DL1 is capable of decomposing organic matter, removing sulfites, resistant to pathogenic microorganisms shrimp Vibrio sp and accumulating co-enzyme Q10. The Department of Intellectual Property, Ministry of Science and Technology granted in 2021
- Scientific papers in referred journals (list):
1. Do Thi Lien , Do Thi To Uyen, Hoang Phuong Ha, Cung Thi Ngoc Mai, Nguyen Thanh Huyen, Le Thi Nhi Cong (2019). Methods for harvesting purple non sulfur bacterial biomass to create a liquid paste for sulfide treatment in aquaculture ponds. Jounal of Vietnamese Environment: (Technical University of Dresden, Germany). Special. Issue. APE 2019, 2193- 6471, 52 – 59.
2. Do Thi Lien, Do Thi To Uyen, Hoang Phuong Ha, Cung Thi Ngoc Mai, Le Thi Nhi Cong (2020). Selection some sources of carbon to produce biomass of VKTQH containing high protein for food bivalve animal breeds. Proceedings of  2020 Viet Nam National Conference on Biotechnology, 486-493.
3. Do Thi Lien, Do Thi To Uyen, Hoang Phuong Ha, Cung Thi Ngoc Mai, Nguyen Van Ngoc, Huynh Thi Huong, Le Thi Nhi Cong (2021). Study on some affects for hight biomass production of S purple non sulfur bacterial in natural condition. Proceedings of 2020 Viet Nam National Conference on Biotechnology, 1118-1123.
- Technological products (describe in details: technical characteristics, place):
+ 50 kg of liquid paste of purple non sulfur bacteria products as food for bivalves breed animals rand 50 kg of liquid paste of purple non sulfur bacteria products for sulfide and organic treatment (We were used in shrimp ponds and used as supplemented food for bivalves breed animals in Cuu Dung company).  
+ The production process of purple non sulfur bacteria products can be applied liquid paste for the treatment of the bottom of aquaculture ponds and supplemented food for bivalves breed animals.
- Other products (if applicable):
+ Participating in training 1 master's student Huynh Thi Huong, Faculty of Biotechnology, Vietnam Academy of Science and Technology. She was successful defense of master's thesis on January 16, 2022 with the content: Research on creating liquid paste of photosynthetic purple bacteria products as food for bivalves breed animals. Scientific supervisors: Dr. Do Thi Lien and Dr. Le Thi Nhi Cong.

Aquaculture areas in the country.

The obtained results are completely new and have practical application in Vietnam. The results obtained from the project need to be developed and replicated. Therefore, it is necessary to continue researching, developing and perfecting production technology on a large scale and commercializing products so that consumers can access them.