Gracilaria tenuistipitata var Liui were mono cultivated and co cultivated with Pinctada martensii under high (33) and low (21) salinity conditions in laboratory. The daily growth rate of the alga was determined. Tissu...Gracilaria tenuistipitata var Liui were mono cultivated and co cultivated with Pinctada martensii under high (33) and low (21) salinity conditions in laboratory. The daily growth rate of the alga was determined. Tissue carbon and nitrogen contents, the yield and fractional composition of agar were analyzed. Results showed that: 1. Gracilaria grew better under low salinity conditions, the daily growth rate was twice that under high salinity conditions. Co cultivated algae grew faster than mono cultivated algae under low salinity conditions, the daily growth rate was about 37.6% higher. 2. Compared with mono cultivated algae, tissue nitrogen contents of co cultivated algae were higher, while the C:N ratios were much lower. 3. The agar yields of co cultivated algae were much lower than those of mono cultivated algae. Agar yield was found to be negatively correlated to the tissue nitrogen contents, and positively correlated to the C:N ratios. 4. The highest fractional yields obtained from co cultivated algae were extracted with 40% ethanol, while from mono cultivated algae, the highest fractional yields obtained were extracted with distilled water at room temperature.展开更多
Gracilaria tenuistipitata varliui Zhang el Xia is cultivated at two different salinities (21, 33) in the laboratory for 4 weeks. The daily growth rate is determined. The total agar yield and fractional agar compositio...Gracilaria tenuistipitata varliui Zhang el Xia is cultivated at two different salinities (21, 33) in the laboratory for 4 weeks. The daily growth rate is determined. The total agar yield and fractional agar composition are analyzed. Results show that algae grow faster in low salinity. The total agar yield is higher under high salinity conditions than under low salinity conditions. Among the eight fractions extracted, the yields of cold water extract and 40% ethanol extract are about the highest In low salinities the yields of autoclaved extract and 60% ethanol extract are higher, while the yield of cold water extract is lower relative to high salinities.展开更多
Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately....Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately. The best growth rate was obtained under the conditions of 32℃, 30 and 240 μmol/（m^2·s） for G. lichenoides, and 24℃, 20 and 200 μmol/（m^2·s） for G. tenuistipitata, respectively. Then a uniform design was used to evaluate the optimal combinations of the three factors. The best conditions for the highest daily specific growth rates （% increase in wet weight） are determined to be 31.30℃, 32.10, and 287.23 lamol/（m^2·s） for G. lichenoides （16.26%/d）, and 25.38℃, 21.10, and 229.07 lamol/（m^2·s） for G tenuistipitata （14.83%/d）, respectively.展开更多
文摘Gracilaria tenuistipitata var Liui were mono cultivated and co cultivated with Pinctada martensii under high (33) and low (21) salinity conditions in laboratory. The daily growth rate of the alga was determined. Tissue carbon and nitrogen contents, the yield and fractional composition of agar were analyzed. Results showed that: 1. Gracilaria grew better under low salinity conditions, the daily growth rate was twice that under high salinity conditions. Co cultivated algae grew faster than mono cultivated algae under low salinity conditions, the daily growth rate was about 37.6% higher. 2. Compared with mono cultivated algae, tissue nitrogen contents of co cultivated algae were higher, while the C:N ratios were much lower. 3. The agar yields of co cultivated algae were much lower than those of mono cultivated algae. Agar yield was found to be negatively correlated to the tissue nitrogen contents, and positively correlated to the C:N ratios. 4. The highest fractional yields obtained from co cultivated algae were extracted with 40% ethanol, while from mono cultivated algae, the highest fractional yields obtained were extracted with distilled water at room temperature.
文摘Gracilaria tenuistipitata varliui Zhang el Xia is cultivated at two different salinities (21, 33) in the laboratory for 4 weeks. The daily growth rate is determined. The total agar yield and fractional agar composition are analyzed. Results show that algae grow faster in low salinity. The total agar yield is higher under high salinity conditions than under low salinity conditions. Among the eight fractions extracted, the yields of cold water extract and 40% ethanol extract are about the highest In low salinities the yields of autoclaved extract and 60% ethanol extract are higher, while the yield of cold water extract is lower relative to high salinities.
基金Supported by the 908 Special Program (908-02-04-07)the National Basic Research Program of China (973 Program, No. 2006CB400608)K. C. Wong Magna Fund in Ningbo University
文摘Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately. The best growth rate was obtained under the conditions of 32℃, 30 and 240 μmol/（m^2·s） for G. lichenoides, and 24℃, 20 and 200 μmol/（m^2·s） for G. tenuistipitata, respectively. Then a uniform design was used to evaluate the optimal combinations of the three factors. The best conditions for the highest daily specific growth rates （% increase in wet weight） are determined to be 31.30℃, 32.10, and 287.23 lamol/（m^2·s） for G. lichenoides （16.26%/d）, and 25.38℃, 21.10, and 229.07 lamol/（m^2·s） for G tenuistipitata （14.83%/d）, respectively.
