Bacteria interact and are a constant in our day to day lives, perhaps more than suspected. Bacteria are often thought of as bad, however this is untrue, there is also many types of ‘good’ bacteria. ‘Good’ bacteria can benefit us by simply helping our digestive system work and helping us in the process of fermentation.
Bacteria are extremely helpful in the production of many things such as fuel and medicine. But bacteria directly affect our production of food which, therefore, directly affects us. Without bacteria we wouldn’t have things like; cheese, sour cream and yoghurt. Bacteria are extremely helpful in the dairy industry as it works within food as a decomposer. Bacteria is needed in cheese as a starter culture, the culture grows in the milk, converting the sugar, lactose, into lactic acid giving the cheese the correct amount of moisture and the correct acidity. Cultures are also used in yoghurt, where it does a similar job as the one done in cheese. The culture is responsible for its taste, texture and once more, its acidity. The viscosity of the yoghurt is determined by its quantity of polysaccharide chains.
Food products other than dairy which use bacteria in their production are; wine, dried meats and health food industries, where yeast, lactic bacteria and starter cultures are used. Bacteria doesn’t stop helping us with food there, some bacteria defend against harmful bacteria and aid digestion. These are all examples of bacteria benefiting human life. Bacteria even help destroy toxins and help the immune system mature (1)! However they’re bad bacteria often found in foods, products like milk can contain less beneficial bacteria which can be harmful. Most bacteria in milk comes from the skin of the cow and in production, however healthy cows equal less bacteria. This means in third world countries such as Uganda, where they often use unhealthy cows and goats as their main source of milk, more bacteria is likely to be within the milk making some ill and passing on disease. In places such as Britain, the milk goes through many processes making sure all or most harmful bacteria have been removed.
An example of when bacteria are really not that beneficial to our lives is disease causing bacteria. Bacterial pathogens can cause things like salmonella (food poisoning). Bacteria can also cause diseases like Cholera. Cholera is a huge killer, killing 120,000 a year and making many others extremely sick. Its bacterium is Vibrio Cholerae which is often killed by acidic conditions in the stomach, where the hydrochloric acid and digestive juice stay. Vibrio Cholerae is often taken in to the body through the ingestion of water contaminated with faecal matter containing the pathogen and rarely the ingestion of food, also containing faecal matter with the pathogen.
Carriers then carry the pathogen; therefore it is able to spread making it very deadly. Unfortunately, cholera has few or no symptoms, so it is hard to tell if someone has Cholera meaning it sometimes spreads unnoticed. A symptom which can be linked with cholera is diarrhoea, meaning many carriers are often left being severely dehydrated. The amount of deaths that Cholera causes really reflects on how much this disease affects our lives. In 2010 and 2011, certain areas went through the major cholera epidemics, these were; Haiti, the Dominican Republic, Central Africa and the Pacific region with Papua New Guinea. The major cholera epidemic started in Haiti in October 2010, and it also affected its close neighbouring country, the Dominican Republic. At the end of 2011 (when the outbreak was still ongoing) there were 522,335 cases of cholera and 7001 deaths had been reported by the 25th of December in Haiti (2).
Another example of bacteria benefiting us is bacterial vaccines. Bacterial vaccines are full of killed or attenuated bacteria. It seems crazy to inject bacteria which cause very harmful diseases into the body; however since they are dead they are not able to harm the body. But they do activate the immune system as it recognises it as foreign so it has to attack the bacteria. The immune system starts to produce antibodies for that particular bacteria and these build up and build up until there is enough to destroy the bacteria, this bacteria and antibody is then are remembered by memory cells meaning that next time they are infected with that bacteria the immune system instantly recognises the bacteria therefore killing it straight away, preventing the disease and preventing the same bacterial infection later.
One example of a bacterial vaccine is the Tuberculosis vaccine (3). The BCG vaccine is the most common vaccine. It gets to over 80% of all new born children in the countries which are part of the national childhood immunisation programme. In 2011, in the countries who were hoping to vaccinate each and every child, the levels of use of the vaccine ranged from 53% in Equatorial Guinea and 54% in Ethiopia, to more than a much larger 99.5% in India and China, two largely expanding countries (4). The increase of vaccinations in poorer areas of the world has lead to a much higher life expectancy, greatly affecting our lives.
Bacteria are majorly affecting every single one of us in our lives, from common colds or to making cheese. The ‘good’ and ‘bad’ bacteria help and harm us. Overall, bacteria affects our lives more than any other and are highly beneficial and dangerous.
(1) – http://www.effca.org/content/bacteria-food-production
(2) – http://www.who.int/gho/epidemic_diseases/cholera/epidemics/en/ (3) – http://www.drugs.com/drug-class/bacterial-vaccines.html (4) – http://www.tbfacts.org/bcg-tb-vaccine.html