Isolation and Identification of Lactic Acid Bacteria from Mature Coffee Cheries: Potential Application in Coffee Husk Ensiling

Abstract

Coffee is one of the most profitable crops in Latin America. Brazil is the biggest producer, consumer and exporter in the world. After coffee processing only 5.8% of the total matter is used for coffee production generating a large amount of waste, were no commercial value, that can hardly pollute the environment. The coffee husk conservation can be made by silage. Specific microorganisms can produce a standard ensilage when added in the process. The main goal of this work is to study the natural microflora present in the coffee husk and coffee pulp able to ensilage these by-products. The lactic acid bacteria responsible for this process were isolated and characterised and added in an ensilage process to accelerate the acid lactic production. First, in this work, fresh fruity coffee pulp were put fermented naturally and it was observed that the pH was maintained around 4 during two months. Then many bacteria were isolated from these natural fermented materials. Morphology, fermentative and biochemistry studies were used to identify and characterise the bacteria. These bacteria were able to grown in a coffee extract and change the pH 6 to around 4.4. Then, the second study was added these isolated bacteria in processed coffee husk to ensilage. It shows that is necessary to add the lactic acid bacteria to initiate the ensilage process. In the coffee husk fermentation, 10⁷ CFU were added per g of matter and the pH was maintained around 4.8; microorganisms were viable for 2 months.