Fungus-Mediated Green Synthesis Of Nano-material Using Aspergillus Terreus And Their Appliactions

Fungus-Mediated Green Synthesis of Nano-material Using Aspergillus terreus and their appliactionsAs important metal, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) have received increasing attention due to their unique catalytic and Bioaffinity properties, they have a number of applications, from electronics and catalysis to infection prevention and medical diagnosis. To date, a number of physical and chemical strategies were employed for the synthesis of AgNPs and AuNPs. However, concern has been raised on the toxicity of chemical agents used in AgNPs synthesis. Thus, it is essential to develop a green approach for AgNPs production without using hazardous substances to the human health and environment. Compared with the traditional synthetic methods, biological systems provide a novel idea for the production of nano-materials. Up to now, several microorganisms from bacteria to fungi have been reported to synthesize inorganic materials intracellularly, and thus to be potentially utilized as eco-friendly nanofactories.The silver resistance of bacteria limits the yield of biosynthesis using bacterium, Compared with bacteria, filamentous fungi have been known to secrete much higher amounts of bioactive substances and the bioreduction of Ag using filamentous fungi are extracellular which reducing the influence of silver ions on the cell, all these advantages make fungi more suitable for large-scale production of noble metal nanomaterials. In addition, the extracellular biosynthesis using fungi could also make downstream processing much easier than bacteria.Aspergillus terreus is a fungus commonly used in industry to produce important organic acids, such as itaconic acid and cis-aconitic acid. It was also the initial source for the drug mevinolin (lovastatin), a drug for lowering serum cholesterol. A wealth of experience for its fermentation and processing has been accumulated. The biosynthesis of AgNPs and AuNPs using A. terreus opens a new avenue for the green synthesis of nano-materials.Firstly Silver nanoparticles (AgNPs) were synthesized using a reduction of aqueous Ag+ion with the culture supernatants of A.terreus. The reaction occurred at ambient temperature and in a few hours. The bioreduction of AgNPs was monitored by ultraviolet-visible spectroscopy, and the AgNPs obtained were characterized by transmission electron microscopy and X-ray diffraction. The synthesized AgNPs were polydispersed spherical particles ranging in size from1to20nm and stabilized in the solution, the presence of stabilizer in the cultrue supernatants such as protein and polysaccharide are crucial to the size and shape control of nanoparticles in such a biosynthesis system. The whole reaction process does not need to add any toxic chemicals, the synthesis reaction can occur at room temperature of20-37℃and little impact of nano-silver,has been showed on the environmental pH6-9,the silver ion conversion rate are74.21%.Furthermore, the antimicrobial potential of AgNPs was systematically evaluated. The synthesized AgNPs could efficiently inhibit various pathogenic organisms, including three kinds of bacteria and six kinds of fungi. Combined sensitivity test shows that the synthesized AgNPs can used in conjunction with FCZ and ICZ, Since the biosynthesized AgNPs showed considerable antifungal activity, they could be potential to be widely used in clinical applications.Reduced nicotinamide adenine dinucleotide (NADH) was found to be an important reducing agent for the biosynthesis, and the formation of AgNPs might be an enzyme-mediated extracellular reaction process. The ability to synthesize AgNPs as potential anti-microbial agents using A. terreus is highly promising for the green, sustainable production of nano-metals, and also enhances its widespread application as an important strategy.Secondly, AuNPs were synthesized extracellularly by A.terreus at room temperature. The AuNPs were quite stable without using any toxic chemicals as capping agents. The synthesized AuNPs were polydispersed spherical particles and the majority of the particles were less than5nm, no significant side effects were observed. The biosynthesised AuNPs were usd in a NO-PCR for optimize the a mp lifi c a t io n e ffe c t ive ly, A uN Ps ar e va l u a b le f o r imp r o vin g th e PC R a mp lif i c at io na n d th e w o rk a lso e x te n d s it s ap pl ica t io n i n th e f ie ld o f bio lo g y.As p e rg il l u s te rre u s is a fu ng u s c o mmo n ly o f g r e a t us e in in du st ry, a nd th ew ho le ge no me se q u e nc ing has also be e n c o mp le t e d, ho w e ve r th e me c ha n ism s d et ailsth a t un d e rl ie A. te rre u s re main un ch a r a c t e r iz e d o w in g to th e la c k o f e ffic ie n t g e n et icme th o d s. In th is w o rk it is th e fir s t t i me to e s t a blis hm e n t of th e Ag roba c te riu m-me di a t e d tr a nsf o rm a t io n (A TM T) s ys t e m T he tr a ns f o rm a t io n s yst e m inc lu d e s th eu s ing o f A. te rre u s c o nid ia as sta r t i n g ma t e r ia l a nd A. tu m e fa c ie ns st ra in A G L-1ha rb o ri ng bin a ry ve c t o r p BH t1as D N A d o no r, A f t e r c o-c ul t iva t io n fo r48h a t20°Cin th e d a rk, tr a nsf o rm a nt s are selec t e d o n S M c o nt a in ing200μ g/m l hyg ro myc in B.T he tr a ns fo rm a t io n e ffic ie n cy re ach m o r e th a n120tr a ns fo rm a n t s pe r106c o nid ia andth e p os it iv e ra te is ne a rl y to100%. T he hi g h ly e ff ic ie n t tr a ns fo rm a t io n e na b le d u s to o bt a in a la rg e nu mb e r o f A. te rreu s T-D N A ins e r t io n mu t a g e ne sis w it hin a sh o rt e xp e ri me nt a l p e ri o d. The se mu t ant s a r e mit o ti c s t a bili t y, s c le a r g e ne t ic ba c k g ro un d sa n d in s e rt i o n sit e s ra ndo mly. Th er m a l a s ymm e t r ic in t e rl a c e d PC R (T ail-PC R) are u s e d fo r re c o ve ri n g th e T-D N A in se r t io n s it e w it h g e n o me-w id e inf o rm a t io n o f.T h isme th o d ma y p ro v id e a ne w in si g h t f o r mo le c u la r ba s ic a nd G e ne t ic a lly mo d ify o fth is imp o rt a nt fun g u s.In a ll, w e e st a blis h e d a no vel pr o c e s s f o r th e g r e e n s yn t he s is o f na n o-ma t eri alsu s in g A. te r re us. It o p e n s a new ave nu e f o r th e gr e e n s yn t he s is o f na n o-ma t e ri als. A n d a ls o e xt e nds it s a p pl ica t io n in t he f i e ld o f bio lo g y a nd me di c in e. It is a n us efu la t te mp t of th e me di c a l na n o mat eri al s s ynt h e s is p r o c e s s a n d a p p lic a t io n.