Rotifers are considered as one of the most important prey organisms in the culture of altricial fish larvae. However, high density rotifer culture is often problematic due to water quality problems which results in fr...Rotifers are considered as one of the most important prey organisms in the culture of altricial fish larvae. However, high density rotifer culture is often problematic due to water quality problems which results in frequent crashes. In the present study, the performance of a small-scale, continuous system was evaluated for culturing rotifers, Brachionus plicatilis, using concentrated nonviable green algae, Nannochloropsis oculeataas feed in a 160 L tank for a period of 90 days. The system configuration was simple and major components consisted of a protein skimmer and a pure oxygen delivery system. Although egg ratio increased from 3% on day 1 to 21.8% and 39.3% on days 7 and 9, respectively, rotifer growth was slow at start up and resulted in fluctuations in total number of rotifers between days 19-41. Rotifer densities remained 〈 400 until day 51 but increased at higher rates reaching 900 individuals/mL on day 55, 1,620 on day 60 and 2,127 on day 70. Rotifer density reached a maximum of 2,188 individuals/mL on day 85. Once the rotifer density exceeded 1,500 individuals/mL （day 60）, periodical harvesting （a total of 16 harvest events） produced a total of 369,920,000 rotifers corresponding to a daily production of 12,330,667 individuals/day during the next 30 days until the experiment was terminated at day 90. As a result of periodic harvesting, water makeup and continuous protein skimming, total settleable solids and NH3-N levels remained low and ranged between 4-22 mL/L and 0.4-2.2 mg/L, respectively. The authors＇ findings indicated that this inexpensive culture system can be successfully used for small-scale marine or freshwater ornamental fish production. Further work is required to minimize lag period at start-up and increase the production potential and yield by better management of suspended solids.展开更多
To improve the process of “Attiéké” production by the standardization of the traditional inoculums, the effects of inoculums amount (6%, 8%, 10% and 12%) and fermentation time (6, 12 and 18 h) were studied...To improve the process of “Attiéké” production by the standardization of the traditional inoculums, the effects of inoculums amount (6%, 8%, 10% and 12%) and fermentation time (6, 12 and 18 h) were studied and analyzed for their microbiological and sensory qualities using standard analytical procedures. The microbial analysis showed that Lactobacillus species (9.14 Log cfu/g) as the most important popular microorganism in the paste, followed by enterococci (7.64 Log ufc/g) species, yeasts and moulds (7.30 Log cfu/g) respectively. Sensory analysis revealed significant effects (p < 0.05), of inoculums quantity and fermentation time on the “Attiéké” quality. “Attiéké” obtained with 10% inoculums and after 12 hours of fermentation was identified as the optical inoculums amount and time for “Attiéké” production. The importance of traditional starter inoculums in “Attiéké” processing could be necessary to standardization at small and industrial scale the process of production.展开更多
文摘Rotifers are considered as one of the most important prey organisms in the culture of altricial fish larvae. However, high density rotifer culture is often problematic due to water quality problems which results in frequent crashes. In the present study, the performance of a small-scale, continuous system was evaluated for culturing rotifers, Brachionus plicatilis, using concentrated nonviable green algae, Nannochloropsis oculeataas feed in a 160 L tank for a period of 90 days. The system configuration was simple and major components consisted of a protein skimmer and a pure oxygen delivery system. Although egg ratio increased from 3% on day 1 to 21.8% and 39.3% on days 7 and 9, respectively, rotifer growth was slow at start up and resulted in fluctuations in total number of rotifers between days 19-41. Rotifer densities remained 〈 400 until day 51 but increased at higher rates reaching 900 individuals/mL on day 55, 1,620 on day 60 and 2,127 on day 70. Rotifer density reached a maximum of 2,188 individuals/mL on day 85. Once the rotifer density exceeded 1,500 individuals/mL （day 60）, periodical harvesting （a total of 16 harvest events） produced a total of 369,920,000 rotifers corresponding to a daily production of 12,330,667 individuals/day during the next 30 days until the experiment was terminated at day 90. As a result of periodic harvesting, water makeup and continuous protein skimming, total settleable solids and NH3-N levels remained low and ranged between 4-22 mL/L and 0.4-2.2 mg/L, respectively. The authors＇ findings indicated that this inexpensive culture system can be successfully used for small-scale marine or freshwater ornamental fish production. Further work is required to minimize lag period at start-up and increase the production potential and yield by better management of suspended solids.
文摘To improve the process of “Attiéké” production by the standardization of the traditional inoculums, the effects of inoculums amount (6%, 8%, 10% and 12%) and fermentation time (6, 12 and 18 h) were studied and analyzed for their microbiological and sensory qualities using standard analytical procedures. The microbial analysis showed that Lactobacillus species (9.14 Log cfu/g) as the most important popular microorganism in the paste, followed by enterococci (7.64 Log ufc/g) species, yeasts and moulds (7.30 Log cfu/g) respectively. Sensory analysis revealed significant effects (p < 0.05), of inoculums quantity and fermentation time on the “Attiéké” quality. “Attiéké” obtained with 10% inoculums and after 12 hours of fermentation was identified as the optical inoculums amount and time for “Attiéké” production. The importance of traditional starter inoculums in “Attiéké” processing could be necessary to standardization at small and industrial scale the process of production.
