【作者】 焦帅；

【导师】 阮榕生；

【作者基本信息】 南昌大学 ， 食品科学， 2010， 硕士

【摘要】 食用菌味道鲜美,含有丰富的蛋白质、多种氨基酸和维生素等营养成分,是一种健康长寿的绿色保健食品。然而,随着工业三废的大量排放,含重金属离子的化肥、农药、除草剂等的使用,以及食用菌栽培原料来源的多样化,食用菌中重金属含量超标的问题日益凸现出来。因此,严格控制好食用菌中重金属的含量以提高食用菌的食用安全性,对我国食用菌产业的发展具有深远的意义。本文研究了重金属对平菇和香菇菌丝生长和菌落形态的影响。结果表明,Hg2+对平菇菌丝的毒性强于Pb2+,培养基中Pb2+、Hg2+含量分别为50mg/L、15mg/L时,与基础培养基中的平菇菌落直径相比,开始呈现显著性差异；培养基中重金属Hg2+、Cd2+分别为10.0mg/L、1.0mg/L时,严重影响香菇菌落生长和改变菌丝形态。在重金属达到显著抑制菌丝生长的浓度的培养基中分别添加碱土元素、微量元素和阴离子元素后,发现钙、磷酸二氢铵缓解重金属对平菇菌丝的毒害效果较好,尤其钙元素；培养基中添加果胶、植酸后,都能够缓解重金属的毒害作用,其中植酸的解毒效果优于果胶。当植酸的浓度为0.1-2.0g／L时,对平菇中重金属Hg2+的解毒效果最佳；当植酸的浓度为3.0g／L时,对Pb2+的解毒效果最佳。向培养基中添加米糠、光皮树籽粕后,米糠的解毒效果强于光皮树籽粕,米糠和光皮树添加量均为20.0g／L时,对平菇所受到的重金属毒害表现出显著的解毒效应。对于香菇而言,米糠和光皮树籽粕对缓解香菇受Hg2+、Cd2+毒害的效果也非常明显。米糠和光皮树籽粕对Hg2+的解毒效果都非常明显,而对于Cd2+而言,光皮树籽粕对Cd2+的解毒效应要优于米糠。在果胶和植酸对重金属选择吸附性试验中,植酸对重金属的吸附能力远远强于果胶,尤其是在pH=10条件下,植酸对Pb2+、Hg2+的吸附量分别为对照溶液中重金属含量的84.7%和67.7%,即每克植酸可吸附固定Pb2+和Hg2+分别为0.85mg/g、0.68mg/g;Hg2+的吸附作用明显优于光皮树籽粕。米糠对Pb2+、Hg2+的吸附平均吸附量分别为Pb2+:3.11mg/g、Hg2+:1.05mg/g;而光皮树籽粕的平均吸附量分别为Pb2+：2.94mg/g、Hg2+:0.96mg/g。稻草栽培试验结果显示,Ca2+元素在缓解平菇Hg2+富集能力方面的作用非常明显。对比未被Hg2+污染的栽培料(配方1、4),平菇子实体中的Hg2+累积量比配方1中减少39.87%,平菇产量也提高26.03%；对于被Hg2+污染的栽培料(配方3、6)而言,石灰处理的栽培料Hg2+累积富集量仅为未经石灰处理的61.01%。在被Pb2+污染的栽培料中(配方2和5),经过石灰处理过的栽培料平菇中Pb2+累积富集量比未经石灰处理中的下降20.6%,平菇Pb2+含量合格率提高20.0%。木屑栽培结果表明,被重金属污染的栽培料添加米糠、光皮树籽粕、磷酸二氢铵后,平菇产量有所提高,而且米糠和光皮树籽粕对重金属的解毒效果非常明显,尤其是米糠；被重金属污染的栽培料中添加米糠后,与被Hg2+污染的栽培料(配方3)中平菇Hg2+含量存在显著性差异(P=0.041),Hg2+累积富集量为3.64mg／kg,比被Hg2+污染栽培料中的降低了56.05%；对比被Pb2+污染栽培料中平菇Pb2+含量发现,添加米糠和光皮树籽粕的栽培料,平菇中Pb2+累积富集量为7.19mg/kg、8.16mg/kg,比被Pb2+污染的栽培料中Pb2+含量降低了55.86%、49.91%,而且添加米糠栽培料(配方7)中的平菇Pb2+含量与配方2中的存在显著性差异(P=0.048),因此,米糠在Pb2+的解毒效应方面最好。更多还原

【Abstract】 Edible fungus, which contain a lot of nutritions such as protein, amino acids, vitamins, are a delicious and healthy food. However, as the emission of industrial waste, the use of pesticides and herbicides containing different heavy metals, the sources diversification of cultivation materials of edible fungi, the problem of the excessive content of heavy metal ions in edible fungus increasingly outstanding.Therefore, we need to control the content of heavy metals in edible fungi to enhance the food safety of edible fungi which has far-reaching significance to the edible fungus industry in China.In this paper, we studied the effects of heavy metals on mycelium growth and colonial morphology of Lentinus edodes and Pleurotus ostreatus. The results showed that the toxicity of mercury to mycelium growth of Pleurotus ostreatus is more serious than that of lead, the significant differences of mean growth diameter of basic medium and medium contaminated by heavy metals appeared, when the concentrations of lead and mercury were 50mg/L,15mg/L;the mycelium growth and colonial morphology of Lentinus edodes were seriously affected when the concentrations of mercury and cadmium in medium were 10.0mg/L,1.0mg/L.When the medium were added on alkaline earth elements, trace elements under the condition that the concentrations of the heavy metal seriously restrained the mycelium growth, we found that calcium and Ammonium Dihydrogen Phosphate could well mitigated the poisonous effect of heavy metals on Lentinus edodes mycelium, particularly the calcium; when adding pectin and phytic acid into medium, they were able to alleviate the toxic effects of heavy metal to mycelium of Pleurotus ostreatus, the detoxification of phytic acid was better than that of pectin, and when concentration of phytic acid was 0.1-2.0g/L, the detoxification to mercury added into medium was the best, when concentration was 3.0g/L, the best to lead; in the experiment about rice bran and Swida Wilsoniana Oilcake, we found that the detoxification of rice bran was better than Swida Wilsoniana Oilcake, when the content of rice bran and Swida Wilsoniana Oilcake were 20.0g/L, the detoxification to heavy metals was obvious.The research about Lentinus edodes told us that rice bran and Swida Wilsoniana Oilcake also had very significantly effects on restraining the toxicity to mercury and cadmium. Their detoxification to Hg2+ was apparent, but the Swida Wilsoniana Oilcake’s detoxification to Cd2+ was better than the that of rice bran.In the absorption tests of phytic acid and pectin to heavy metals, the absorption ability of the phytic acid is much higher than the pectin. Especially at the condition of PH was 10, in which the absorption capacity of heavy metal to phytic acid was 84.7% (0.85mg/g) and 67.7%(0.68mg/g) compared with the blank sample solution respectively; in the absorption tests of rice bran and Swida Wilsoniana Oilcake to heavy metals, the absorption ability of rice bran to lead and mercury was significantly better than that of Swida Wilsoniana Oilcake,the average absorption contents of rice bran to lead and mercury were 3.11mg/g,1.05mg/g respectively, Swida Wilsoniana Oilcake were 2.94mg/g,0.96mg/g.The result of the experiment of cultivation materials using straw showed that the calcium could significantly reduce the richment ability of mercury in fruiting bodies of Pleurotus ostreatus. Compared with the accumulation content of mercury in fruiting bodies of Pleurotus ostreatus cultivated by Formula 1, Formula 4 was decreased by 39.87%, and the yield of Pleurotus ostreatus also increased by 26.03%; for cultivation materials dealing with two methods (Formula 3,6), the accumulation content of mercury in fruiting bodies of Pleurotus ostreatus cultivated by Formula 6 was at only 61.01% of Formula 1’s.However, the accumulation content of lead in fruiting bodies of Pleurotus ostreatus cultivated by Formula 5 was decreased by 20.6% comparing with that of Formula 2, and the qualification yield of concentration of lead in fruiting bodies increased by 20.0%.The results of the experiment of cultivation materials using sawdust revealed that the production of Pleurotus ostreatus increased when the rice bran, Swida Wilsoniana Oilcake and Ammonium dihydrogen phosphate were added into cultivation materials which were contaminated by heavy metals,and detoxification of rice bran and Swida Wilsoniana Oilcake to heavy metals were very distinct, especially the rice bran’s,when it added into cultivation materials which was contaminated by heavy metals,there was significant differences about the content of mercury in fruiting bodies of Pleurotus ostreatus between it and the contaminated cultivated material, in contrast with Formula 1, the accumulation content of mercury in fruiting bodies cultivated by Formula 3 was 3.64mg/kg,and decreased by 56.05%; when rice bran and Swida Wilsoniana Oilcake were added into the cultivation materials which were contaminated by lead, the accumulation contents of lead in fruiting bodies of Pleurotus ostreatus were 7.19mg/kg,8.16mg/kg respectively, compared with the contaminated cultivation materials,they decreased by 55.86%,49.91%,especially there was significant differences about the content of lead in fruiting bodies of Pleurotus ostreatus between different cultivation materials (Formula 7 and Formula 2),therefore,the rice bran was the best at the detoxification to lead.更多还原