Evaluation The Relative Mycelial Biomass Of Edible Fungi In Culture Medium By DNA Testing

Growth is an important life processes in all the biologies,we can distinguish or observe most of the animals and plants'growth and development processes clearly by naked eyes, we usually use the words of"size","weight"to describe the individual's growth.Because of the mycelium mixed with the culture substrates in the fungi edible mycelium growth stage,we had to use the words like"thick","thin","white"or"neat"et al. to desicribe the mycelium growth non-quantifiable,which can not accurately quantify the condition of their growth.Due to the mycelium conducted a series of metabolic activities in the culture medium,there has been a series of technical difficulties to determine the fungi mycelium biomass which is mixed with the culture medium.In this study,we used the detected DNA content to certain the biomass of mycelium,measuring the edible fungi mycelium biomass in the culture medium by using the indirect method mainly.We used the Lentinus edodes,Strain 135,and Flammulina velutipes as the experimental materials to evaluation the relative mycelial biomass which is mixed with the culture medium in this experiment.Firstly, prior to construction of a standard curve suitable for application to edible fungi,preliminary experiments were carried out to determine the optimal conditions for mycelium culture and DNA extraction, and the range of mycelial biomass over which a linear relationship with extracted DNA was observed.We constructed standard curves relating DNA concentration with mycelial biomass for three separate batches of L.edodes and F.velutipes.The correlation coefficient for each batch was >0.99,the standard curves have high reproducible,low error range.Our data indicated that,under controlled conditions,extracted DNA concentrations exhibited a linear relationship with mycelial biomass whereby one milligram (dry wt) of mycelium corresponded to 6.11±0.34μg and 36.49±0.83μg DNA from L.edodes and F. velutipes,respectively.Therefore,our data indicate that both the quantity and quality of mycelium were affected by subtle changes in the growth medium and the subcultured mycelium.The standard curves relating biomass with DNA content obtained using mycelium grown on PDB obtained from a commercial source were more reproducible.We also found that the DNA content is different between L.edodes and F. velutipes,that is to say,when evaluating the test smples,we need to construct the corresponding standard curve for the target species.Secondly,because of the culture medium all are agricultural waste,there may be associated with different levels of DNA content by themselves,we measured the DNA content of the corresponding culture substrates of L.edodes and F. velutipes.The results shown that the culture media of both Lentinus edodes Strain 135 and F.velutipes have different levels of DNA values,whereby one milligram (dry wt) of culture substrates corresponded to 0.689±0.080μg and 0.522±0.044μg DNA from L.edodes and F. velutipes,respectively.Prior to evaluate the relative mycelial biomass in the different medium,we should determinate the DNA content of the corresponding culture media,which is required to get the accurate mycelial biomass.Again,we studied the interference that culture substrates posed on the DNA extraction of the mycelium in this article,mixed the standard culture mycelium with the corresponding culture substrates by a certain percentage,testing the DNA content of the mixture to determinate the culture substrates interference of L.edodes and F. velutipes in this experiment conditions,the value is 0.030±0.032 and 0.030±0.013 for respectively.The data indicated that the culture media are different,the DNA content of the culture media may be the same,but the affect rate which culture substrates posed on the DNA extraction of the edible fungi mycelium is different.Finally,based on the above-mentioned,we evaluation the mycelial biomass of the L.edodes Strain 135 culture bags which taken back from Zhejiang Lishui and mycelium which were cultured in the flask,obtained the unit mass of the Lentinus edodes Strain 135 mycelium biomass parameters which is mixed with the culture substrates,and estimated the measurement error range.We also evaluation the mycelial biomass at different growth stages of F.velutipes which collected from Shanghai Gaorong Agriculture Co.Ltd,established the DNA consumption model by the obtained data.Then,we have a initial understanding of the relative mycelial biomass at different growth periods in the culture medium.This is the first time using the DNA testing to evaluate the relative mycelial biomass of the edible fungi in this study.While in the construction of the method,the measurement error range is considering,too(the single point error range of the different repeat is less than 18%,experimental determination of the average error range is less than 3%).Compared to the previous evaluation of microbial biomass difficultly,no systematic and reliable detection methods,can not be estimated error range,provide a new way of thinking from this method of the constructed for accurately evaluation the microbial biomass in the culture substurates.