CAJ | 학술논문

　　为探讨高碳酸盐碱度水质对江蓠的影响,本研究对比分析了高HCO3?浓度(12、24、36、48 mmol/L)与低HCO3?浓度(1.8 mmol/L)条件下细基江蓠繁枝变型(Gracilaria tenuistipitata var. liui Zhang et Xia)的生长及生理生化特征。经过10 d的培养后发现高 HCO3?浓度组中江蓠的特定生长率(SGR)显著高于对照组(P<0.05),表明高 HCO3?浓度有利于促进江蓠的生长。随着 HCO3?浓度的增加,江蓠的叶绿素 a、藻红素、类胡萝卜素含量呈逐渐下降趋势,丙二醛含量呈增加趋势。当HCO3?浓度从1.8 mmol/L增加到24 mmol/L时,江蓠SGR、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性呈增加的趋势,而从24 mmol/L增加到48 mmol/L时,这3种指标均呈下降趋势。相关分析表明,江蓠 SGR 与 SOD 活性呈显著的正相关关系(P<0.05),说明 HCO3?浓度的增加对江蓠生长产生一定胁迫作用,但其具有由抗氧化酶形成的自身防御系统,能够在一定 HCO3?浓度范围内保护藻体。在本实验条件下,江蓠对高 HCO3?离子具有较强的耐受能力,其生长的最适HCO3?浓度为24 mmol/L,超过这一浓度对江蓠生长的促进作用有所减弱。本研究旨在通过探讨大型海藻对高 HCO3?浓度的生长及生理生化适应性,为运用大型经济海藻对高碳酸盐型盐碱水域开发利用的可行性提供科学依据。
　　위탐토고탄산염감도수질대강리적영향,본연구대비분석료고HCO3?농도(12、24、36、48 mmol/L)여저HCO3?농도(1.8 mmol/L)조건하세기강리번지변형(Gracilaria tenuistipitata var. liui Zhang et Xia)적생장급생리생화특정。경과10 d적배양후발현고 HCO3?농도조중강리적특정생장솔(SGR)현저고우대조조(P<0.05),표명고 HCO3?농도유리우촉진강리적생장。수착 HCO3?농도적증가,강리적협록소 a、조홍소、류호라복소함량정축점하강추세,병이철함량정증가추세。당HCO3?농도종1.8 mmol/L증가도24 mmol/L시,강리SGR、초양화물기화매(SOD)화과양화물매(POD)활성정증가적추세,이종24 mmol/L증가도48 mmol/L시,저3충지표균정하강추세。상관분석표명,강리 SGR 여 SOD 활성정현저적정상관관계(P<0.05),설명 HCO3?농도적증가대강리생장산생일정협박작용,단기구유유항양화매형성적자신방어계통,능구재일정 HCO3?농도범위내보호조체。재본실험조건하,강리대고 HCO3?리자구유교강적내수능력,기생장적최괄HCO3?농도위24 mmol/L,초과저일농도대강리생장적촉진작용유소감약。본연구지재통과탐토대형해조대고 HCO3?농도적생장급생리생화괄응성,위운용대형경제해조대고탄산염형염감수역개발이용적가행성제공과학의거。
The total amount of dissolved inorganic carbon in water includes CO2, H2CO3, HCO3?, and CO32-. At a pH of between 8.2–8.4, HCO3?is the predominant component (approximately 90%), and free CO2 contributes less than 1%. In China, saline-alkali water covers about 45.87 million ha, most of which is characterized by high car-bonate alkalinity (CA) concentrations. Since high CA is a major stressor for living organisms, most of these sa-line-alkali water areas have little evidence of life. To take advantage of this unexploited resource, researchers have trialed the use aquatic plants to reduce the HCO3?concentration in saline-alkali waters. The seaweed Gracilaria tenuistipitata var. liui Zhang et Xia is characterized by rapid growth and easy cultivation. The objective of this study was to investigate the effects of high HCO3?concentrations on the growth, physiology, and biochemistry of G. tenuistipitata to provide basic information for the development of saline-alkali water using macroalga. G. tenuisti-pitata were grown for 10 d in a 250 mL Erlenmeyer flask containing 200 mL culture medium with 1.8 (control), 12, 24, 36, or 48 mmol/L HCO3?. We then compared the physiological and biochemical characteristics of G. tenuisti-pitata among the different treatment groups. The water temperature(25℃±1℃), salinity (20), initial pH (8.2-8.4), light intensity (5 000 lx), light-dark cycle (12D︰12h), and algae density (5 g/L) were the same for all groups. The specific growth rates (SGR) of G. tenuistipitata in the high HCO3?concentration groups were significantly higher than in the control after 10 d exposure (P<0.05), suggesting that the increase in HCO3?enhanced growth in G. te-nuistipitata. The effect may have been mediated by an increase in the available carbon (e.g., CO2) in the water. The increase in HCO3?was associated with a gradual decrease in chlorophyll a, phycoerythrobilin, and carotenoid content in G. tenuistipitata, suggesting the increase in HCO3? had a negative effect on the synthesis of of photosynthetic pigments, and led to membrane lipid peroxidation. In addition, the SGR and superoxide dismu-tase (SOD) and peroxidase (POD) activity increased in G. tenuistipitata as the concentration of HCO3? increased from 1.8 to 24 mmol/L, then decreased in the range between 24 to 48 mmol/L. HCO3? content was significantly correlated with the content of chlorophyll a (P<0.01), phycoerythrobilin, carotenoids, and malonaldehyde (P<0.05). SGR was significantly correlated with SOD activity (P<0.05), but not with the content of photosynthetic pigments, suggesting that the inhibitory effect of high HCO3?concentration on the growth of G. tenuistipitata may damage the antioxidant system, not the photosynthetic system. With regard to the growth of G. tenuistipitata, high HCO3? concentrations appear to be beneficial by increasing the availability of inorganic carbon for the photosyn-thesis. However, the tradeoff is the production of CO ?which forms a CaCO3 precipitate with Ca2+, reduces the 2 3 synthesis of photosynthetic pigments, and causes damage to the membrane system. The antioxidant defense system appeared to protect G. tenuistipitata at HCO3?concentrations of <24 mmol/L. However, antioxidant activity (e.g., SOD and POD) was significantly impaired at HCO3?concentrations of>24 mmol/L, suggested the defense system was damaged. As a result, the SGR of G. tenuistipitata was lower at these concentrations. Based on our results, an HCO3? concentration of 24 mmol/L appears optimal for the growth of G. tenuistipitata, and concentrations <24 mmol/L appear to be detrimental.