In most buildings, warmth and moisture are the biggest overall issues present. availability to facilitate growth of microorganisms. 7.3 Influences of environmental factors on growth 1. Bacteria by virtue of mechanical strength of their cell wall are able to … 7 0 obj endobj • Growth factors are organic compounds that are essential cellular components or precursors of these components but cannot be synthesized by the organism • Major Classes of Growth factors 1. amino acids 2. purine and pyrimidines 3. vitamins (e.g., thiamine, biotin, cobalamin, pyridoxine) Intrinsic factors include those that are internal to the food product itself, such as nutrient content, pH levels, water activity, redox potential, and other antimicrobial components acting as defense mechanisms against microbes. 1. endobj Use the terms that describe a microbe’s growth range or requirement for each of the factors that influence microbial growth 2. *�,N:���_FجiWIʃ�sY.��,2j3���Q���c,d�/��>oFyQ��������9�������W����?��:k턺��BJꪀ�u=��M&m��oE]��>�1�ki@a��bj�)7�%/Y+/x�_��� ��.�@�57f���p�p��r���V� ��:k����` �mlw�m��PQ���]�*!/t�ji�qq���T�:�:c�hΕ�V���a*��O8>'Ԛ����(6��8���������sew��x���V���������/F�^����;��j��AyO-�z�����}W�̸��{�8o�yٿQ�:��Uпw��� ",#(7),01444'9=82. The factors affecting microbial survival and growth in foods determine the nature of spoilage and any health risks. 5 0 obj These include natural food compounds, preservatives, the oxidation-reduction potential, aw, and pH. Metabolic processes Primary metabolism of an organic compound has been defined as the use of the substrate as a source of carbon and energy. As our foods are of plant and animal origin, it is worthwhile to consider those characteristics of plant and animal tissues that affect the growth of microorganisms. factors that affect organisms because they are in excess (e.g.,. Temperature is the most important factor that determines the rate of growth, multiplication, survival, and death of all living organisms. One indicator of microbial response is their taxonomic classification. Effect of oxygen availability 7. Compounds affecting microbial enzymes (oxidative agents, chelating agents, heavy metals, antimetabolites) Compounds reacting with DNA ( chemical mutagenes – alkylating or deaminating agents, cytostatics) It is notable that each microbial species possesses a definitive pH growth range and a distinctive pH growth optimum (Fig. %PDF-1.5 Nutrients needed by microorganisms include: Carbon carbon containing compounds are needed as an energy source (ex. Microbial membrane are disrupted by temperature extremes. Most muscle foods have low levels of carbohydrates. N��q��r�dˎ�o��\�o�X�K���-�y����[������9�g��C@2�?�;|tT�����k�������ӱ���$���[*��&zKH��ӒV�0_�OKZôqE�6!��%c���. Main factors affecting microbial growth 5. 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