Research On The Resource Utilization Of Shell,Meat And Egg Of Golden Apple Snail (Pomacea Canaliculata)

Invasive species golden apple snail Pomacea canaliculata(Lamarck)is a harmful pest in reducing agricultural production in many parts of Asia.The sustainable and environmental-friendly methods to control its invasion are urgently needed.In this study,six amendments,namely the residues at the levels of 0.5,1,2.5,25,50,100 g kg^-1,shell,meat of snails and lime at the levels of 0.5,1,and 2.5 g kg^-1along with a blank soil(control),were,respectively,added to an acid soil(p H=6.37)and incubated for 120 days to determine how the amendments at different levels affect soil p H,soil nutrients,microbial communities and enzyme activities;Folch method of phospholipids extraction from muscle was used with some modifications(the best ratio of mixed solvent,chloroform:methanol:water,2:1:0.8)to evaluate the feasibility of extracting phospholipids from golden apple snails body and eggs.Altogether,this study was conducted to explore the environmental-friendly utilization of golden apple snail's body and residues.Results showed that at low levels amendment(0,1,2.5 g kg^-1),lime could sharply increase soil p H from 6.37-7.90,while no significant difference in soil nutrients was found;snail's meat could decrease soil p H from 6.37-5.13,while increase soil NO₃-N from3.78-11.85 mg kg^-1,NH₄-N from 1.82-6.55 mg kg^-1,TOC from 16.04-18.46 g kg^-1;the amendment of snail's shell could increase soil p H from 6.37-7.43,while there was no significant changes of soil nutrients;interestingly,the amendment of snail's residues could increase soil p H from 6.37-7.28,and increase soil nutrients(for NO₃-N from 3.78-9.66 mg kg^-1and for NH₄-N from 1.82-2.26 mg kg^-1).Shifts in soil nutrients and soil p H were significantly correlated with fungal and actinomycetes community composition and observed changes in extracellular enzyme activities.Powered snail's residues have been used to alleviate soil acidification and degradation,while its potential effects on bacterial diversity and community composition at taxonomic level remain unclear.High-throughput pyrosequencing(16S r RNA)analyzed 39 soil samples collected from incubated columns in greenhouse.Totals of 2016767 high-quality 16S r RNA gene sequences were generated and classified.The results of alpha diversity estimators show that both snail's residues and lime amendments could increase bacterial diversity at low level amendment while decrease trend were found at high level amendment.Compared with the control,more abundant and specialized bacterial communities were found in snail's residues treatments rather than lime treatments,and Proteobacteria,Firmicutes,Chloroflexi,Actinobacteria,Acidobacteria,Gemmatimonadetes,Cyanobacteria and Bacterioidetes are the dominant phyla in samples.Significant correlations of dominant bacterial communities to soil properties,including soil p H and nutrients,were found in snail's residues treatments,while soil p H is the main indicator responsible for the bacterial community composition changes in lime treatments.Extracellular enzyme activities were increased in snail's residues treatments while they were not influenced at low level lime amendments and decreased at high level lime amendments.These results suggest that the amendment of snail's residues could significantly increase bacterial diversity at low level amendments,and improved soil p H is responsible for these effects as low-level amendment of lime does,while significantly decrease bacterial diversity through improving soil nutrients.Soil nutrients other than soil p H may as better predictors for bacterial diversity and communities'composition in snail's residues treatments soil.This study suggests that the golden apple snail residues can be used to alleviate the acidized and degraded soil by increasing soil p H,nutrients and microbial activities,and to control the invasion of golden apple snails.Phospholipids extracted from the meat and eggs of golden apple snail were identified using high performance liquid chromatography coupled with electrospray ionization-tandem mass spectrometry(HPLC-ESI–MS/MS).The extraction efficiencies of coarse phospholipids are 12.38-20.10%in snail's meat and 5.61-8.23%in snail's eggs,and for PC that are 0.24-0.54%in meat and 0.06-0.08%in eggs.Overall,this study suggests that the golden apple snail residues can be used to improve soil quality by neutralizing soil p H as well as by increasing nutrient availability,microbial species,and enzyme activities.Golden Apple Snail's meat can be a raw material for lecithin extraction.More importantly,this pollution-free approach would also trigger farmers'motivations to actively collect living golden apple snails for controlling their invasions in China and southeastern Asia.