Optimal Liquid Spawn Conditions and Grain Medium Enhanced Hispidin Production by Phellinus linteus in Solid-State Fermentation

This study aimed to screen a highest hispidin production of strain from 12 strains of Phellinus, and to evaluate the effects of liquid spawn conditions and grain medium on this strain’s hispidin production levels after solid-state fermentation. Results showed that the P. linteus 04 led to the highest hispidin production, this strain was then selected to elucidate the optimal liquid spawn conditions and grain medium for hispidin production. Various liquid spawn conditions were evaluated, and the highest hispidin yield, specific productivity of hispidin, and total content of hispidin were found to be optimal at 1 week of liquid spawn age, cultured with potato dextrose borth, and using 10 % inoculum rate, with each condition resulting to 0.350, 0.325, and 0.328 mg/g dry weight of mycelium, 0.352, 0.251, and 0.249 µg/mg week− 1 specific productivity, 57.90, 60.23, and 61.77 mg/kg dry weight of brown rice medium, respectively. These liquid spawn conditions were then used to determine the appropriate grain medium for hispidin production. The highest hispidin yield and total content of hispidin were observed in pearl barley which resulted in 1.107 mg/g dry weight of mycelium and 199.76 mg/kg dry weight of pearl barley, which led to results that were 4.73-fold and 5.35-fold higher than those of control (brown rice medium). Overall, this study shows that P. linteus hispidin production can be enhanced by solid-state fermentation using optimal liquid spawn conditions and the appropriate grain medium.

Optimization of Technical Parameters on the Medium Formulation and Culture Conditions in Production of Pleurotus eryngii Liquid Spawn

Liquid spawn, an important technical support for industrial production of edible fungi, has some advantages, such as fast growth, strong activity, uniform quality and easy inoculation. However，the study of the fermentation parameters of Pleurotus eryngii liquid spawn is less, which cannot effectively guide the production practice. Therefore, in order to provide a theoretical basis for the production of liquid spawn and industrial production of Pleurotus eryngii, response surface analysis was used to optimize the liquid spawn formula and conditions. The best carbon and nitrogen source of liquid medium was glucose and yeast extract, respectively. The optimum formula of medium was obtained by response surface analysis. Combined with the practical operation, the formula was modified to 29.00 g/L glucose, 2.90g/L yeast extract, 0.90g/L KH2PO4 and 1.00g/L MgSO4. The effects of various factors on the dry weight of mycelia were analyzed, the results indicated that the influence follow the sequence: glucose, KH2PO4, yeast extract and MgSO4, among them, the first two factors had significant effect. The interaction between glucose and KH2PO4 had obviously effects on the dry weight of mycelia. The interaction between glucose and yeast extract had a certain effect. The optimum culture conditions of liquid spawn were obtained by response surface analysis. Combined with the actual situation, the conditions were modified to liquid volume 106.00mL/250mL, rotating speed 165.00r/min, temperature 23.60℃, initial pH 6.70. The effects of various factors on the dry weight of mycelia was analyzed, the results indicated that the influence follow the sequence: initial pH, liquid volume, temperature and rotating speed, among them, the first three factors had extremely significant effect. The interaction of liquid volume and rotating speed, temperature and initial pH had obviously effects on mycelial dry weight.

Changes of Physiological Characteristic Indexes in the Aging Process of the Liquid Spawn of Auricularia auricula

In order to explore the change rule of physiological indexes during the aging process of the liquid spawn of Auricularia auricula, this test chooses three species of Auricularia auricula(Hei29, Heiweibanjin and Heiweidanpian), which treasured the activities of antioxidant enzymes, antioxidant substances, membrane peroxidation degree and reactive oxygen concentration during different mycelia age. The conclusion showed that: at the same mycelial age, the vitality of Heiweidanpian was the strongest, Hei29 followed, and Heiweibanjin was the weakest; with the increase of mycelia age, Catalase (CAT) activity, Ascorbic Acid(ASA) content, Malondialdehyde (MDA) content and O2- production rate of the three kinds of Auricularia auricula increased continuously. Among them, ASA content, MDA content and O2- production rate increased significantly, while Superoxide Dismutase (SOD) activity decreased significantly; although the Proline (Pro) content and electrical conductivity of the three kinds of Auricularia auricula showed different trends, which decreased significantly at 14 to 16d and increased significantly at 8 to 10d, respectively, and H2O2 content increased significantly at 12 to 16d. It can be seen that SOD activity, CAT activity, ASA content, MDA content and O2- production rate have significant regular changes during the aging process of the liquid spawn of Auricularia auricula. The quantitative analysis found that when the MDA content is 1.42~1.72 μmol·g-1, the H2O2 content is 3.4~4.3 μmol·g-1 or the O2- production rate is 9.5~12.1 μmol·g-1·min-1, it can be considered Auricularia auricula just started to age or the aging degree is relatively low.

Immobilization of Mycelial Pellets from Liquid Spawn of Oyster Mushroom Based on Carrier Adsorption

We investigated a practical method for immobilizing liquid spawn of oyster mushroom (Pleurotus ostreatus) to prolong the storage time and provide convenient transportation of liquid spawn of edible mushrooms. The method was based on the mycelial pellets of liquid spawn adsorbed in carriers. Selected carriers were similar to cultivation substrates, and the best carrier was a mixture of cottonseed hull, corn core, and wheat bran with a ratio of 4.5:4.5:1 by weight. Immobilized spawn were prepared by mixing the pellets from liquid spawn with carriers using a ratio of 1:8 by weight. Within the first 15 days of storage at 20–25 °C, the immobilized spawn grew strongly, respiration intensity and cellulase activities rose rapidly, and the count and brightness of the isozyme bands of esterase, peroxidase, and polyphenol oxidase increased remarkably as well. From days 30 to 60, the cellulase activities fell and the brightness of the peroxidase and polyphenol oxidase bands gradually decreased, whereas the respiration intensity and the band count of esterase and peroxidase remained constant. After 60 days, the cultivated characteristics of the immobilized spawn were same as the fresh conventional solid cottonseed hull spawn. The results showed that immobilized spawn on the basis of the mycelial pellets of liquid spawn adsorbed in carrier can be used to extend the storage time and simplify transportation of liquid spawn of edible mushroom.