User:Jimmyjon12/Fibrobacter succinogenes

= Fibrobacter succinogenes = Fibrobacter succinogenes is an bacterium that degrades cellulose in the rumen of herbivores. F. succinogenes is a gram negative, rod- shaped, obligate anaerobe that is a major contributor to cellulose digestion. Since its discovery in the 1950s, it has been heavily studied for is significance in herbivores and its role in cellulose fermentation that can be utilized in biofuel production.

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History
Fibrobacter succinogenes was isolated in 1954 by M.P. Bryant and R.N. Doetsch from bovine rumens at the University of Maryland. In their study, they isolated 8 different strains - S23, S61, S85, S111, S121, C2, M13, and M34. They found that all of these strains belonged to one species - Bacteroides succinogenes - which would later be renamed to Fibrobacter succinogenes. S85 would soon become the model strain for study, and it would remain that way since it continues to be representative of wild type species.

Genome
The genome of F. succinogenes is 3.84 Megabasepairs and is predicted to consist of 3085 open reading frames. Many of these genes encode for carbohydrate binding molecules, glycoside hydrolases, and other enzymes. 31 genes are identified as cellulases. The genome also encodes for a number of proteins capable of breaking down sugars, but it lacks the machinery to transport and use all the products except for those derived from cellulose.

Metabolism
F. succinogenes utilizes an orthogonal lignocellulose metabolism making it an efficient degrader of cellulose. This unique metabolism differs form other model cellulose degraders like Clostridium thermocellum and Trichoderma reesei which use cellulosomes and cellulose secretion systems, respectively. Cell adhesion to their cellulosic substrate is suggested to play a role in efficiency which could explain why F. succinogenes is such an efficient degrader.

F. succinogenes main metabolic machinery is in the cell envelope or periplasmic space. Depending on the type available cellulose, this bacteria will make a different set of proteins and enzymes necessary to degrade each type. It's been found that the degradation enzymes covalently bind to the outer surface of the cell. These enzymes have carbohydrate binding molecules that improve degradation by bringing substrates closer to the active sites of degradation enzymes. F. succinogenes is capable of breaking down many sugars, but only so that it can gain better access to cellulose, it sole food source. When grown on cellulose, the cell down-regulates other surface sugars and proteins, but and up-regulation of surface lipids. This regulation of other surface elements favors the formation and use of cellulose degrading enzymes.

No amino acids are required for growth, so NH4+ is the sole nitrogen source essential to protein production. PO4---, NH4+, Mg++, Ca++, K+, and Na+ are all essential for growth. F. succinogenes can use glucose, but grows best on cellulose in the absence of glucose.

Application to Biofuels
Biofuel production currently relies on use of feedstocks that could also be used for food. Alternative sources of feedstocks are available, but expensive to use. Cellulose, hemi-cellulose and lignocellulose can be used as alternatives. Using these sources to make biofuel is a 2 step process - 1. saccharification 2. fermentation. Saccharification is a pre-treatment that creates viable sugars for fermentation and is the bottlenecking step due to being expensive and energy intensive. Current feedstocks, such as corn grain, can skip this step since they are high in starches and can be readily fermented.

Since Fibrobacter succinogenes is an efficient saccharifier of cellulose, it has a high potential to be used in the biological degradation of cellulose for biofuel production.

Outline:

History

Bryant et al

metabolism

- Use metabolism image from ref 1

https://www.nature.com/articles/s41598-019-52675-8

Diversity

* https://microbewiki.kenyon.edu/index.php/F._succinogenes

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3079729/

https://www.tandfonline.com/doi/abs/10.1080/10408410490435133

https://journals.asm.org/doi/10.1128/mSphere.00593-18

https://onlinelibrary.wiley.com/doi/full/10.1111/j.1740-0929.2004.00207.x?casa_token=9GI7Q6vgbb8AAAAA%3AiVgIpoL0tnaYU40fQBItr1kPiBumn06-3VtgAoW2Rc4IBuGiK6G5UZin8S1wdEC_wjznLW5udLpsuHrx4g

https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/fibrobacter-succinogenes

https://www.sciencedirect.com/science/article/pii/S002203025990815X

https://reader.elsevier.com/reader/sd/pii/S0022030254913879?token=31F369031E830725F70095192C03FE41B9B9ACACB416C2B6143D5F9448546350C1DC3FC227D970D08C105117D7EC8320&originRegion=us-east-1&originCreation=20220927230921

https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-018-1290-x

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC383150/#r7