NOVELTY - A mutant trichodiene producing filamentous fungus (F1) having the trichothecene pathway comprises: (a) a specific disrupted gene or a mutant gene having low P450 monooxygenase production; and (b) a modified nucleic acid sequence encoding for at least one gene selected from 3 genes as given in the specification. The sequence is modified such that the filamentous fungus produces at least 10% more trichodiene than the parent filamentous fungal cell when cultured under the same conditions.    USE - For the production of trichodiene using a biomass growth media selected from a sugar, starch, cellulose, and hemicelluloses (claimed); trichodiene is useful as a liquid biofuel.    ADVANTAGE - The modified filamentous fungus produces at least 10% more trichodiene than the parent filamentous fungal cell when cultured under the same conditions. The modified fungus produces trichodiene from non-food related feed-stocks such as lignocellulose, for biofuel production.    DETAILED DESCRIPTION - A mutant trichodiene producing filamentous fungus (F1) having the trichothecene pathway comprises: either (i): (a) a specific disrupted gene, or a mutant gene having low P450 monooxygenase production (Tri4), and (b) a modified nucleic acid sequence (A1) encoding for at least one gene selected from 3 specific genes as given in the specification (Tri5, Tri6 and Tri10); or (ii): (a) the modified nucleic acid sequence (A1) encoding for at least one of the genes selected from (Tri5, Tri6 and Tri10) to increase the production of the gene product, and (b) the presence of a Tri4 inhibitor to inhibit at least a portion of the Tri4 gene product. The filamentous fungus produces at least 10% more trichodiene than the parent filamentous fungal cell when cultured under the same conditions. An INDEPENDENT CLAIM is included for producing (M1) trichodiene involving: (a) selecting a mutant filamentous fungus having the trichothecenes pathway comprising: (i) a disrupted Tri4 gene or a mutant Tri4 gene having low P450 monooxygenase production and the fungus in combination with a Tri4 gene product inhibitor, and (ii) a modified nucleic acid sequence encoding for at least one of the genes selected from Tri5, Tri6 and Tri10; (b) cultivating the mutant filamentous fungus using a biomass growth media selected from a sugar, starch, cellulose, and hemicelluloses; and (c) isolating trichodiene from the growth media; where the filamentous fungus produces at least 10% more trichodiene than the parent filamentous fungus when cultured under the same conditions and using the same growth media.