NOVELTY - A blend comprises a hydrocarbonaceous composition; and an aminoalcohol derivative.    USE - As a blend for providing microbial resistance to a biodiesel fuel i.e. petroleum and liquid fuels (claimed).    ADVANTAGE - The aminoalcohol additives improve the corrosion properties and microbial resistance (bacterial or fungal resistance) of hydrocarbonaceous compositions, such as petroleum and fuels. The aminoalcohol additives also enhance the efficacy of biocidal agents typically used in such compositions. In addition to improved corrosion stability and microbial resistance, the primary aminoalcohols synergistically enhance the activity of biocides in hydrocarbonaceous compositions. The combination of the aminoalcohol and the biocide provides more effective and longer-lasting microbial control at reduced biocide concentrations than would be expected if the biocide was used alone. The biocide (or combination of biocides) is present in the blend at a concentration of 0.001-2 wt.%. In order to reduce cost and minimize potential for adverse environmental impact, it is preferred that low concentrations of biocides be used. Indeed, it is one of the advantages that by enhancing the efficacy of the biocide, the aminoalcohols permit less biocide to be used than could be achieved without the aminoalcohol.    DETAILED DESCRIPTION - A blend comprises a hydrocarbonaceous composition; and an aminoalcohol derivative of formula R1-C(OH)(R3)-R6-C(NH2)(R4)-R2 (I).    R1 and R3=H, linear or branched alkyl, alkenyl, alkynyl, cycloalkyl, or aryl;or    R1, R3 and the carbon to which they are attached=cycloalkyl ring;    R2 and R4=H or alkyl;    R=absent or is a 1-10C alkylene, arylene, arylene-alkylene-, or -alkylene-arylene-.    Where the aminoalcohol contains at least 5 carbon atoms, and where alkyl, cycloalkyl, alkylene, aryl, and arylene are optionally substituted with alkyl or phenyl. Provided that R2 and R4 together contain 2 or fewer carbon atoms. An INDEPENDENT CLAIM is included for providing microbial resistance to a biodiesel fuel, involving including the aminoalcohol derivative (I) in the biodiesel fuel.