Habib Sarsangi Aliabad, Abolfazl Naji, Seyed Reza Seyed Mortezaei, Iman Sourinejad, Arash Akbarzadeh,
Volume 10, Issue 3 (9-2021)
Abstract
Biofloc technology has mentioned as a new tool for sustainable aquaculture development and has overcome the problems of water scarcity and discharge of aquaculture effluents to the environment. In this system, nitrogenous wastes (Ammonia and Ammonium) are simultaneously recovered by bacteria and converted into microbial proteins that can be consumed by aquatic animals. The purpose of this study was to investigate the factors affecting the production of biofloc and evaluate it for use in aquaculture. The effect of different temperature levels (24, 28, 32 °C), salinity (0, 4, 8 g/l) ,and C/N ratio (10:1, 15:1, 20:1) which are the main key factors to the formation and function of biofloc system was evaluated by using a response surface method designing. Moreover, the influence of those factors on total ammonia nitrogen, nitrite, nitrate, floc volume, protein, and lipid content of biofloc was investigated. The results showed that the temperature had a significant effect on floc volume and protein content of biofloc (P < 0.05), but it had no significant effect on other nitrogenous compounds and lipid content (p > 0.05). The protein, lipid and moisture of biofloc particles were decreased by increasing salinity significantly (P < 0.05). Also, TAN and nitrite concentration influenced by C/N ratio inversely. According to the factors Optimization, providing 27 °C and C/N ratio of 18:1 in brackish water and 29 °C and C/N ratio of 14:1 in fresh water resulted in high quality biofloc production and control of nitrogenous wastes in water.
Volume 19, Issue 7 (12-2017)
Abstract
Supplementation to increase the quality and yield of white button mushrooms (Agaricus bisporus) consists of the addition of nutrients, particularly proteins, to the compost. In this study, the effect of mushroom cultivation on applying a delayed-release nutrient supplement to Phase II composts was evaluated. Two application dosages and composts with high nitrogen contents were used. Depending on the compost and supplement dosage used, increases in biological efficiency ranging between 6.2 and 22.3% were obtained. An excellent response to supplementation can be obtained even when using composts with high nitrogen contents (in our case, 2.45 and 2.61% sms) during spawning. It is additionally conceivable that the application of supplements to composts with lower N contents or the application to spawned compost would provide an even better yield, without adversely affecting the quality of the harvested mushrooms. This practice is of considerable interest because of the economic benefit.
