Microbial infestation

Perkins, R. D. Tsentas, C. I. (1976). Microbial infestation ofcarbonate substrates planted on the St. Croix shelf, West Indies. Geological Society of America Bulletin, 87,1615-28. 

Figure 3.8 Different types of microbial infestation of fruit trees. 

MICROBIAL INFESTATION OF WOOD-PLASTIC COMPOSITE MATERIALS... 

High levels of microbial infestation are also characteristic of sandy soils, when they are polluted. Increased BM in sands leads to an increase... 

In general, for end uses where a polymer dispersion will be in contact with an environment conducive to the propagation of microbial infestation, a contaminated product cannot be ignored as a possible source of further contamination. All the effects detailed above, resulting from microbial spoilage of polymer dispersions, must be fully investigated in terms of product quality complaints because they can lead to significant economic loss to the manufacturer if products reach the consumer in a deteriorated condition. 

The doses applied for the widely used microbial decontamination by irradiation of spices, dried herbs, and dry vegetable seasonings (see Sec. 4.9) are much higher than the disinfestation doses. Thus radiation decontamination of these commodities is more than enough to kill also any insects eventually infesting them. 

The aroma compounds from the tropical fruits described in this chapter can be very important for consumers and industry as they are exotic and extremely pleasant however, the production of these compounds by biotechnological processes should be emphasised since the extraction from the fruits is a hard task. Many tropical soils contain less nitrogen and phosphorus, have lower capacity to absorb fertilisers, and therefore have lower conventional productive capacity, but some tropical soils have been very intensively farmed and further intensification is possible in other areas. Thus, the evaluation of a sustainable agriculture in tropical regions requires a sophisticated approach including the estimation of the risk of microbial or insect infestations. As many fruits go directly to fresh markets or to immediate processing, a continuing supply of the flavour manufacturers in the future is not completely assured. 

Each bag or container of raw materials should be identified with a unique code, lot, or receipt number. This code should be used in recording the disposition of each lot. Raw materials will be held under quarantine until they are sampled, tested, and released. Raw materials should be carefully handled and stored to avoid any contamination or cross contamination. When bagged and boxed raw materials need to be stored, it must be done so in adequately cleaned buildings that are free of infestation by rodents, birds, insects, and other vermin, and the building should be maintained. A controlled environment may be necessary to avoid microbial contamination or degradation caused due to exposure to heat, air, or light. When the raw materials are stored outdoors, the containers should be adequate for the outdoor storage. 

Sediment Slow microbial degradation due to tight bonding of adsorbed Diquat to the clay minerals on the sediment (shake flask-liquid scintillation spectrometry, Simsiman Chesters 1976) t,/2 > 158 d for 1.5 pg/mL of infested sediment-water microcosm to biodegrade (derived from results of Simsiman Chesters 1976 Muir 1991). 

Composite decking materials are manufactured under heat and pressure to encase the cellulosic fiber in the plastic, resulting in a product with high resistance to weathering, moisture, insect infestation, and decay. In reality, the encasement is never complete, which leaves room for water absorption, thermal- and UV-induced oxidation with oxygen from the air, and microbial contamination. 

Any treatment used to reduce fungal/microbial contamination or other infestation should be documented. Instructions on the conduct of such procedures should be available and should include details of the process, tests and limits for residues. 

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