Purification of liquid products of cotton wipes biotransformation with the aid of Trichoderma viridae in orbital flight
Abstract
Recovery of various organic wastes in space flight is an actual problem of modern astronautics and future interplanetary missions. Currently, organic waste are incinerated in the dense layers of the Earth's atmosphere in cargo containers. However, this method of anthropogenic waste treatment is not environmentally compatible with future interplanetary missions, and is not suitable due to planetary quarantine requirements. Furthermore, the maintaining of a closed ecosystem in spaceship is considered as one of the main ways of ensuring the food and air crew in the long term fully autonomous space expedition. Such isolated ecosystem is not conceivable without biotransformation of organic waste. In this regard, currently new ways of recycling organic waste are currently developed. The most promising method is a method for processing organic waste using thermophilic anaerobic microbial communities.However, the products of anaerobic fermentation of solid organic materials contain significant amounts of organic impurities, which often give them sour pH. This presents a significant problem because it does not allow to use this fluid as process water without pretreatment. Fermentation products - alcohols, volatile fatty acids other carbonaceous substances must be withdrawn.One way to solve this problem may be the use of microorganisms biodestructors for recycling organic impurities in the products of anaerobic biodegradation Under the proposed approach, the metabolic products (having acidic pH) of primary biotransformation of solid organic materials are used as media for the cultivation of fungi. Thus, cellulosic wastes are recycled in two successive stages. The aim of this work was to test the effectiveness of post-treatment liquid products of biodegradation of hygienic cotton wipes (common type of waste on the ISS) by the fungus Trichoderma viridae under orbital flight. The study was conducted onboard biosatellite Bion -M1, where was placed a bioreactor, designed to carry out the fermentation in space flight. For aerobic post-treatment of substrates remaining after biodegradation of cotton wipe there was selected a strain of the fungus Trihoderma viridae, able to grow at a slightly acid environment , and to bring the pH to neutral values. Bioreactor working volume of 40 ml, where 20 ml of liquid subjected to post-treatment was placed. Strain Trihoderma viridae, isolated from ISS environment, showed steady growth in terms identical to those of pre- cultivation. Efficiency of purification was assessed using the method of gas chromatography-mass spectrometry comparing the amount and concentration of the volatile organic compounds in the samples. It turned out that the number of compounds detected in the flight sample almost halved compared to the original sample obtained after biodegradation gauze anaerobic bacteria. The total concentration of volatile impurities dropped 6 times. Thus, despite the limited resource of oxygen, due to lack of aeration in the bioreactor strain Trihoderma viridae demonstrated the ability to perform aerobic purification of substrate obtained after anaerobic biodegradation of cotton wipes under orbital flight.
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E3511V