| In recent years,bamboo mildew inhibitor from plants has been favored by many researchers at home and abroad.As the chemical substances in traditional bamboo mildew inhibitors not only pollute the environment but also are toxic to humans and animals,exploring new green bamboo mildew inhibitors that are harmless to humans and animals and environmentally friendly has gradually become a research hotspot.Many studies have shown that many natural plant extracts and essential oils in nature have the effects of antiseptic,mildew and insect resistance.Toddalia asiatica(L.)Lam.is a genus of the Rutaceae family.According to the study,it has the ability to promote blood circulation and disperse blood stasis,dispel wind and dampness,relieve swelling and pain,anti-inflammatory and antibacterial effects,and eventually is a traditional national medicine.In our paper,the main fungal species causing bamboo fungus were firstly isolated and identified from the moldy bamboo samples and used as test fungi for subsequent experiments.Then,the extracts were extracted from the roots,stems and leaves of Fei Long Jia Blood by ultrasonic-assisted extraction with anhydrous ethanol and ethyl acetate,and the fungal inhibitory activity of the extracts was tested against four species of bamboo fungi,and the mycelial growth rate method was used to evaluate the fungal inhibitory effect of the extracts from the three parts of Fei Long Jia Blood.Then the active components of the extracts from the stems and leaves of Toddalia asiatica were identified by GC/MS,and the similarities and differences and the mechanism of action were analyzed.Finally,the bamboo was treated with different concentrations of ethanol extract of Toddalia asiatica leaves,and the indoor mildew resistance test was carried out to evaluate the mildew grade and control efficacy of the treated bamboo,and the changes of chemical composition and micro-structure of the bamboo after mildew and before and after mildew resistance treatment were compared and analyzed.The main conclusions are as follows:(1)Nine mold-causing fungi were isolated and purified from moldy bamboo.The nine fungi were identified and belonged to Apiospora rasikravindrae,Chaetomium globosum,Syncephalastrum racemosum,Neopestalotiopsis saprophytica,Didymella heteroderae,Rosellinia convexa,Fusarium equiset,Arthrinium phaeospermum,and Alternaria tenuissima.(2)The root,stem and leaf of Toddalia asiatica were extracted by ultrasonic wave with two kinds of solvents,which the extracts were tested in vitro.On the 7th day The results showed that when the concentration of the extract was 20 mg/mL,the inhibition rates of the extract against Apiospora rasikravindrae,Didymella heteroderae,Alternaria tenuissima were above 98%,92%,85.9% respectively.However,inhibition rate against Rosellinia convexa was still 100%.In contrast,the antibacterial activity of the three parts of the extract was in the order of root> leaf>stem,while the difference of the antibacterial activity of the leaf and stem was only1.8% and 4.3%.The results showed that the extract from the Toddalia asiatica had the potential to be an environment-friendly mildew inhibitor of bamboo.In fact,the roots of Toddalia asiatica are mainly used for medicinal purposes,while the leaves have not been widely exploited and are often treated as production wastes.Considering the factors of bacteriostatic effect,reducing raw material cost and rational utilization of leaves,this chapter determines Toddalia asiatica leaves and anhydrous ethanol solvent as the raw materials for the subsequent bamboo mildew inhibitor.(3)A total of 41 active ingredients,mainly siloxanes,sesquiterpenes,alcohols,aromatic hydrocarbons,aliphatics,ethers,monoterpenes,alkanes,esters,thick-ringed aromatic compounds,ketones and acids,were identified by GC/MC technique from the anhydrous ethanol and ethyl acetate extracts of the blood stems and leaves of Fei Long Palm.Among them,22 active ingredients were found in the leaf-ethanolic extract,27 in the stem-ethanolic extract,26 in the leaf-ethyl acetate extract and 23 in the stem-ethyl acetate extract of Phyllanthus feijoa blood,respectively.The antibacterial properties of the blood of Fei Long Pawpaw could be the result of the combined action of these compounds.(4)The bamboo material was treated with different concentrations of ethanolic extract of blood leaves of Fei Long Palm by vacuum impregnation and indoor anti-mold experiments,and the results showed that the bamboo material was treated with strong inhibition against all 9 species of molds.When the concentration was at100 mg/mL,which was lower than 80% with an exception of the inhibition rate of Trichoderma globosum.And the inhibition effect of the remaining 8 kinds of molds was higher than 85%,among which the inhibition rate of 4 kinds of molds(Trichoderma neoformans,Trichoderma heterotrophicum,Trichoderma convexum and Streptomyces)had reached 100%;when the concentration was 120 mg/mL,only the Trichoderma globosum could not be completely inhibited,the inhibition rate was80%.The effectiveness of the control of the remaining 8 species of mycorrhizal fungi reached 100%.This suggested that the ethanolic extract of the blood leaf of Fei Long Palm has a strong anti-mold effect on bamboo materials.(5)Comparing the chemical composition and microscopic morphology of bamboo before and after treatment and mildewing,it was suggedsted that the chemical composition of bamboo treated with anti-mildewing agent and mildewing treatment was basically unaffected,and the internal structure could be not changed significantly.In total,this paper mainly explores the antibacterial properties and chemical composition of different parts of extracts of Fei Long Palm Blood,and preferably selects the leaves as the raw material of bamboo anti-mold,which has a good inhibitory effect on various bamboo molds.The experimental results provide a basic theoretical basis for the development of an efficient green plant-derived and anti-mold agent from Fei Long Palm Blood leaves. |
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