Study On The Light Parameters,broken Wall Technology Of Spores From Vinegar Residue Fermented By N.sitophila And Effects Of The Products As Additive On Laying Hens

Light parameters have a great influence on the fermentation of Neurospora,so in this study,we first screened and optimized the light parameters that affect the carotenoid production of Neurospora sitophila.Carotenoids produced by Neurospora sitophila mainly exist in the spores of Neurospora sitophila,and the spore wall is very strong,so the nutrients in the spores are difficult to be digested,absorbed and utilized by animals.Therefore,the technology of breaking the spore wall of Neurospora sitophila was studied.Then,the wall breaking products of Neurospora sitophila spores were added to the diets of laying hens to study the effects of the wall breaking products on production performance and egg quality of laying hens.The main contents are as follows:Taking carotenoid production as detection index,the effects of different color light on carotenoid production from vinegar residue fermented by Neurospora sitophila were compared by single factor experiment.The results showed that red light,yellow light and white light could inhibit the production of carotenoids from vinegar residue fermented by Neurospora sitophila,while green light,blue light and purple light could promote the production of carotenoids,and purple light had the greatest effect on the production of carotenoids,so purple light was selected as the monochromatic light for fermentation of vinegar residue fermented by Neurospora sitophila.Then,Box Behnken design and Response Surface methodology were used to analyze the optimal combination of purple light parameters: purple light intensity 250 Lux,light cycle 11.5 h/d,fermentation time 91 h,the predicted carotenoid yield was 71.38 mg/ kg,and the validation test result was 73.04% ± 54 mg / kg,which was not significantly different from the predicted value(P > 0.05).Compared with the natural light state,the yield of carotenoids was 31.85± 4.03 mg / kg,the carotenoid yield increased by 1.29 times.Taking the carotenoid release amount of Neurospora sitophila spores as the detection index,the single factor test and Placket-Burman test were used to screen the five factors(A,B,C,D,E)affecting the wall breaking effect of spores.The results showed that the order of the five factors affecting the carotenoid release amount was B > A > C > D > E,in which A,B,C had a significant effect on the release of carotenoids from spores(P < 0.05).Then,Box Behnken design and Response Surface method were used to analyze the process parameters of Neurospora sitophila spore wall breaking.The optimal combination of the parameters was as follows: spore 0.05 g,A 0.5,B 3.52,C 5.56,D 30℃,E 15 h,the predicted value of carotenoid release was 999.23 mg / kg,and the validation test result was 1002.91 ± 53 mg / kg,which was not significantly different from the predicted results(P > 0.05).Compared with the method of lactic acid wall breaking,the carotenoid release amount was(1156.25 0 ± 57 mg / kg),the carotenoid release amount of this study was 86.74%.A total of 288 Hailan Brown laying hens aged 250 days were randomly divided into 6 groups(4replicates in each group,12 laying hens in each replicate).They were negative control group(Formula diet),positive control group(Formula diet + 8 mg / kg Canthaxanthin),unbroken spore group(95%Formula diet + 5% unbroken spore and substrate),low-dose group(97.5% Formula diet + 2.5% broken wall products)The middle dose group(95% Formula diet + 5% broken wall products)and the high dose group(90% Formula diet + 10% broken wall products)were fed for 7 days and 28 days respectively.The results showed that: compared with the negative control group,the average daily feed intake and feed to egg ratio of each group had no significant difference(P > 0.05).The analysis of egg quality on the 7th,14 th,21st and 28 th day of normal feeding showed that the spore wall breaking products of Neurospora sitophila had no significant effect on egg shape index,eggshell color,eggshell strength,protein height,Haugh unit,yolk weight and yolk color(P > 0.05).Compared with the negative control group,the carotenoid content in yolk of low-dose group increased significantly and remained unchanged on the 21 st day,and that of medium,high-dose and Canthaxanthin groups increased significantly and remained unchanged on the 14 th day.On the 28 th day,the carotenoid content in yolk of low,medium,high-dose and Canthaxanthin groups increased by 6.67%,11.29%,15.93% and 13.44% respectively.The results showed that: high dose of Neurospora sitophila wall breaking products could significantly improve the total antioxidant capacity(T-AOC)(P < 0.05),medium dose and high dose of Neurospora sitophila wall breaking products could significantly improve the superoxide dismutase(SOD)activity(P < 0.05),At the same time,it could significantly reduce the content of malondialdehyde(MDA)in serum(P < 0.05).Canthaxanthin had no significant effect on the antioxidant function of layers(P > 0.05).In conclusion,the addition of Neurospora sitophila spore wall breaking products to the diet of laying hens had no significant effect on the production performance of laying hens,but could significantly increase the carotenoid content in the yolk,improve the egg quality,and improve the antioxidant function of laying hens.This study laid a foundation for the development of carotenoid functional eggs using cheap vinegar residue.