Current biofuel production relies on limited arable lands on the earth,and is impossible to meet the biofuel demands.Oil producing algae are alternative biofuel feedstock with potential to meet the world’s ambitious ...Current biofuel production relies on limited arable lands on the earth,and is impossible to meet the biofuel demands.Oil producing algae are alternative biofuel feedstock with potential to meet the world’s ambitious goal to replace fossil fuels.This review provides an overview of the biological and engineering aspects in the production and processing technologies and recent advances in research and development in the algae to fuels approach.The article covers biology,selection and genetic modification of algae species and strains,production systems design,culture media and light management,harvest and dewatering,downstream processing,and environment and economic assessment.Despite the many advances made over several decades,commercialization of algal fuels remains challenging chiefly because of the techno-economic constraints.Technological breakthroughs in all major aspects must take place before commercial production of algal fuels becomes economically viable.展开更多
The carbon isotopic composition of organic matter （δ^13Corg） was determined in two sediment cores （IIL1 and IIL9） recovered from Inexpressible Island, Ross Sea, Antarctica, and analyzed to identify the sources of...The carbon isotopic composition of organic matter （δ^13Corg） was determined in two sediment cores （IIL1 and IIL9） recovered from Inexpressible Island, Ross Sea, Antarctica, and analyzed to identify the sources of that organic matter. The δ^13Corg values of sediments of IIL9 were found to vary between -14.6‰ and -11.6‰, with a mean of-13.4‰ （n=48）. These values were significantly higher than those of IIL1 sediments which varied between -23.2‰ and -20.4‰, with a mean of-21.8%o （n=55）. The variation in δ^13Corg values in these two sediment cores indicate different sources of organic matter, The relatively high 6~3Corg values in IIL9 are in accordance with a source from algae, while the low δ^13Corg values in IIL1 evince significant influence from penguin guano with algae as the secondary source. Compared with the reference data from other high-latitude lake sediments and plants, the δ^13Corg values in IIL9 were extremely high, a result likely related to intense competition for CO2 assimilation among algal species during the growing season in this relatively shallow pond. These results indicate that sedimentary δ^13Corg is a reliable proxy for paleo-primary productivity in ponds at Inexpressible Island.展开更多
Reduced walleye (<i></span><i><span style="font-family:Verdana;">Sander vitreus</span></i><span style="font-family:Verdana;"></i></span><spa...Reduced walleye (<i></span><i><span style="font-family:Verdana;">Sander vitreus</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) fingerling production possibly related to nuisance filamentous green algae and overly</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">stable water chemistry patterns is a concern in earthen-substrate ponds at Blue Dog State Fish Hatchery, South Dakota, USA. We describe the success of alfalfa (<i></span><i><span style="font-family:Verdana;">Medicago sativa</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM, n</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">2), alfalfa meal plus soybean (<i></span><i><span style="font-family:Verdana;">Glycine max</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">SBM, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1), and alfalfa meal plus liquid 28N:0P:0K (AFM</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">28:0:0, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1) at achieving</span><span style="font-family:Verdana;"> walleye production objectives (>104,000 walleye and 32 kilograms/hectare) as well as the occurrence of filamentous green algae and the associated patterns of ammonia-nitrogen, pH, and dissolved oxygen in eart展开更多
Pangasius hypophthalmus is the most cultured freshwater fish by smallholder farmers in Indonesia.One of the main challenges in the production is the highly weathered and infertile soils on the bottom of a pond that in...Pangasius hypophthalmus is the most cultured freshwater fish by smallholder farmers in Indonesia.One of the main challenges in the production is the highly weathered and infertile soils on the bottom of a pond that influences aquaculture productivity.This work investigated the effects of pond age on soil quality,water quality,benthic algae population,and P.hypophthalmus production.We carried out a field experiment in a randomized design with pond age of 4 levels:Ponds aged 0-5 years(P1),6-10 years(P2),11-15 years(P3),and 16-20 years(P4).The soil is a Typic Palaeudult(Ultisol),and fish were grown for three months.The results showed that the chemical soil quality parameters and soil organic matter content increased linearly with pond age,resulting in the enhancement of water quality parameters.The increase in nitrate and phosphate directly affected benthic algae richness.These,in turn,in the highest fish production in P3,6.4 kg/m^(2),specific growth rate was 3.76%/d,survival rate of 66.7%,and feed conversion ratio of 1.8%.Linear correlation coefficients indicated that the contents of total N,total P,and organic carbon in the bottom soil of the pond were related to the increase in phosphate,nitrate,and organic matter content in pond water.Total N content,total P,carbon organic matter,C/N ratio,and CEC value in pond bottom soil significantly correlated to Pangus fish production.C/N ratio,CEC value in pond bottom soil,and CO_(2)concentration in pond water significantly correlated to fish survival rate.Multiple linear regression indicated that fish production was significantly related to the pond age,water NH3,total alkalinity,and soil total P and C/N ratio(R^(2)=0.99,P<0.001).Increased soil C/N ratio caused a negative effect on fish production.The results suggested that old-aged ponds,with proper management,act as a nutrient sink,resulting in increased aquaculture production.The implementation of the best practices will benefit the Pangus culture in the tropical environment.展开更多
文摘Current biofuel production relies on limited arable lands on the earth,and is impossible to meet the biofuel demands.Oil producing algae are alternative biofuel feedstock with potential to meet the world’s ambitious goal to replace fossil fuels.This review provides an overview of the biological and engineering aspects in the production and processing technologies and recent advances in research and development in the algae to fuels approach.The article covers biology,selection and genetic modification of algae species and strains,production systems design,culture media and light management,harvest and dewatering,downstream processing,and environment and economic assessment.Despite the many advances made over several decades,commercialization of algal fuels remains challenging chiefly because of the techno-economic constraints.Technological breakthroughs in all major aspects must take place before commercial production of algal fuels becomes economically viable.
基金the Chinese Arctic and Antarctic Administration of the State Oceanic Administration for project supportthe United States Antarctic Program (USAP)+2 种基金Antarctic Support Contract and Italian Mario Zucchelli Station for logistical support. R. Murray and A. Mc Kenzie provided valuable assistance in the fieldsupported by the National Natural Science Foundation of China (Grant nos. 41576183 and 41376124)National Science Foundation (Grant no. ANT 0739575)
文摘The carbon isotopic composition of organic matter （δ^13Corg） was determined in two sediment cores （IIL1 and IIL9） recovered from Inexpressible Island, Ross Sea, Antarctica, and analyzed to identify the sources of that organic matter. The δ^13Corg values of sediments of IIL9 were found to vary between -14.6‰ and -11.6‰, with a mean of-13.4‰ （n=48）. These values were significantly higher than those of IIL1 sediments which varied between -23.2‰ and -20.4‰, with a mean of-21.8%o （n=55）. The variation in δ^13Corg values in these two sediment cores indicate different sources of organic matter, The relatively high 6~3Corg values in IIL9 are in accordance with a source from algae, while the low δ^13Corg values in IIL1 evince significant influence from penguin guano with algae as the secondary source. Compared with the reference data from other high-latitude lake sediments and plants, the δ^13Corg values in IIL9 were extremely high, a result likely related to intense competition for CO2 assimilation among algal species during the growing season in this relatively shallow pond. These results indicate that sedimentary δ^13Corg is a reliable proxy for paleo-primary productivity in ponds at Inexpressible Island.
文摘Reduced walleye (<i></span><i><span style="font-family:Verdana;">Sander vitreus</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) fingerling production possibly related to nuisance filamentous green algae and overly</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">stable water chemistry patterns is a concern in earthen-substrate ponds at Blue Dog State Fish Hatchery, South Dakota, USA. We describe the success of alfalfa (<i></span><i><span style="font-family:Verdana;">Medicago sativa</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM, n</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">2), alfalfa meal plus soybean (<i></span><i><span style="font-family:Verdana;">Glycine max</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">SBM, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1), and alfalfa meal plus liquid 28N:0P:0K (AFM</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">28:0:0, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1) at achieving</span><span style="font-family:Verdana;"> walleye production objectives (>104,000 walleye and 32 kilograms/hectare) as well as the occurrence of filamentous green algae and the associated patterns of ammonia-nitrogen, pH, and dissolved oxygen in eart
文摘Pangasius hypophthalmus is the most cultured freshwater fish by smallholder farmers in Indonesia.One of the main challenges in the production is the highly weathered and infertile soils on the bottom of a pond that influences aquaculture productivity.This work investigated the effects of pond age on soil quality,water quality,benthic algae population,and P.hypophthalmus production.We carried out a field experiment in a randomized design with pond age of 4 levels:Ponds aged 0-5 years(P1),6-10 years(P2),11-15 years(P3),and 16-20 years(P4).The soil is a Typic Palaeudult(Ultisol),and fish were grown for three months.The results showed that the chemical soil quality parameters and soil organic matter content increased linearly with pond age,resulting in the enhancement of water quality parameters.The increase in nitrate and phosphate directly affected benthic algae richness.These,in turn,in the highest fish production in P3,6.4 kg/m^(2),specific growth rate was 3.76%/d,survival rate of 66.7%,and feed conversion ratio of 1.8%.Linear correlation coefficients indicated that the contents of total N,total P,and organic carbon in the bottom soil of the pond were related to the increase in phosphate,nitrate,and organic matter content in pond water.Total N content,total P,carbon organic matter,C/N ratio,and CEC value in pond bottom soil significantly correlated to Pangus fish production.C/N ratio,CEC value in pond bottom soil,and CO_(2)concentration in pond water significantly correlated to fish survival rate.Multiple linear regression indicated that fish production was significantly related to the pond age,water NH3,total alkalinity,and soil total P and C/N ratio(R^(2)=0.99,P<0.001).Increased soil C/N ratio caused a negative effect on fish production.The results suggested that old-aged ponds,with proper management,act as a nutrient sink,resulting in increased aquaculture production.The implementation of the best practices will benefit the Pangus culture in the tropical environment.
