Interesting Facts To Know About Gram +ve VS Gram -ve Microbes

Gram +ve Microbes


Gram -ve Microbes


Gram negative cells tend to be more susceptible to heat and disinfectants as compared to Gram positive. Furthermore, Gram-positive rods tend to have spores while Gram negative bacteria do not. The Gram reaction is a reproducible characteristic of a species and therefore is an additional tool for bacterial identification.

Vacuum packaging can extend the shelf life of some products. This procedure inhibits the Gram-negative bacteria that require oxygen for growth; thus the production of foul odors is delayed. The growth of Gram-positive bacteria, that are also present in the vacuum-packaged product, is a little slower and their metabolic products are not as objectionable. Thus vacuum packaging does not stop spoilage, it only alters the spoilage rate and the nature of spoilage flora. Vacuum packaging, however, carries with it a serious potential hazard because if the product is temperature abused, Clostridium botulinum will be able to grow.

Gram-negative bacteria, such as Pseudomonas, tend to produce more foul odors than Gram-positive bacteria, such a Bacillus or Streptococcus species. Off odors (incipient spoilage) are usually detected when bacterial numbers reach 106 to 107 CFU/G of the product.