Genome Shuffling of Mangrove EndophyticAspergillus luchuensisMERV10 for Improving the Cholesterol-Lowering Agent Lovastatin under Solid State Fermentation

Abstract

In the screening of marine mangrove derived fungi for lovastatin productivity, endophytic Aspergillus luchuensis MERV10 exhibited the highest lovastatin productivity (9.5 mg/gds) in solid state fermentation (SSF) using rice bran. Aspergillus luchuensis MERV10 was used as the parental strain in which to induce genetic variabilities after application of different mixtures as well as doses of mutagens followed by three successive rounds of genome shuffling. Four potent mutants, UN6, UN28, NE11, and NE23, with lovastatin productivity equal to 2.0-, 2.11-, 1.95-, and 2.11-fold higher than the parental strain, respectively, were applied for three rounds of genome shuffling as the initial mutants. Four hereditarily stable recombinants (F3/3, F3/7, F3/9, and F3/13) were obtained with lovastatin productivity equal to 50.8, 57.0, 49.7, and 51.0 mg/gds, respectively. Recombinant strain F3/7 yielded 57.0 mg/gds of lovastatin, which is 6-fold and 2.85-fold higher, respectively, than the initial parental strain and the highest mutants UN28 and NE23. It was therefore selected for the optimization of lovastatin production through improvement of SSF parameters. Lovastatin productivity was increased 32-fold through strain improvement methods, including mutations and three successive rounds of genome shuffling followed by optimizing SSF factors.

Effects of Reduced and Enhanced Glycogen Pools on Salt-Induced Sucrose Production in a Sucrose-Secreting Strain of Synechococcus elongatus PCC 7942

“…M icroorganisms are increasingly being utilized for the commercial production of a variety of products, such as fine chemicals (1,2), health products (3,4), pharmaceuticals (5,6), and biofuels (7,8). An important factor affecting the product price is the cost of the sugar feedstock (9,10).…”

Marine endophytic fungal metabolites: A whole new world of pharmaceutical therapy exploration

“…Regarding to endphytic specificity, some endophytic fungi are Plural species, which are commonly isolated from different types of hosts and from different fragments of the same host (wide host/tissue), and others are specific to a very narrow range of hosts (high specificity, narrow host/tissue range). Neotyphodium endophytes have a narrow host range, being confined to one or two plant species while indigenous abundant endophytic Penicillium , Phoma , and Aspergillus species cover a wide spectrum of taxonomically unrelated host species within diverse genera proposing that they progressed adaptations to overcome diverse kinds of hosts with different function roles and bioactivities [ 5 , 7 , 10 , 33 ]. Another factors contributing to the huge variety detected in endophytic assemblages are geographical difference and host age [ 34 ].…”

“…The certain microbial products appear to be distinguishing of certain biotopes, accordingly it appears that hunting novel drugs with novel modes of action should focus on organisms that reside unparalleled biotopes. In this context microorganisms of unique and unexplored ecological niches such as endophytes that inhabit such biotopes, containing marine plants (like algae, sea-grass, driftwood, and mangrove plants), invertebrates (such as sponge, corals, cruscanceans, ascidans, holothurians, and bivalves), vertebrates (mostly fish) and many other minor marine phyla are currently considered as an outstanding source of bioactive drugs [ 4 , 5 , 6 , 7 , 8 , 9 ]. Fungal endophytes are a polyphyletic category of predominantly ascomycetous fungi that dwell within wholesome host tissues during at least one phase of their life cycle and without affecting any visible symptoms of disease or negative effects on their hosts [ 3 , 10 ].…”

“…The fact that new microbes are usually associated with new natural compounds makes endophytes, with their great genetic variety and undefined species, an effective tool for overcoming deadly diseases, and reducing the de-replication complications in compound discovery. Then it appears clear that prolific and trustworthy sources of bioprospecting tested of fungal endophytes for medical, pharmaceuticals and biotechnological applications are essential for discovering new compounds of multifold importance in drug industry and human health including antibiotics, antimalarial, antiviral and anti-carcinogenesis [ 3 , 4 , 5 , 6 , 7 ]. Since the 1970's there is rising attention in endophytes and their origins, biodiversity, phytism (endophyte-host interactions), their ecological roles with a special interest toward description of their secondary metabolites due to the possibility of these microorganisms to produce a plethora of pharmacologically active natural products [ 6 , 7 , 13 ].…”

“…Endophytic fungi have biotechnology potential in diverse life science applications such as anticancer drugs (taxol, L-asparaginase, L-glutaminase, tyrosinase, and methioninase) [ 5 , 6 , 7 , 14 , 15 , 16 ], antibacterial agents (essramycin, ayamycin, benzopyrones derivatives, and coumarine derivatives) [ 13 , 17 , 18 , 19 ], antifungal agents (saadamycin, and prodigiosin) [ 20 , 21 ], antiviral agents [ 4 , 7 ] and in the biological control of various plague and contaminants [ 15 , 22 , 23 ]. These activities are attributed to the unique products of endophytes including steroids, alkaloids, terpenoids, quaternions, isocoumarin and quinones derivatives, phenolic, flavans and xanthones compounds as well as peptides with pharmaceutical and biotechnology applications [ 1 , 2 , 24 , 25 , 26 ].…”