الفهرس 
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Abstract
Increasing The Levels Of Pollution Overall The World And Especially, In Developing Countries, Claims To Utilize Different Ways To Eliminate Pollutant from The Environment. Of These Pollutants That Represent A Danger On The Environment, A group Called Poly Aromatic Hydrocarbons (Pahs). Pahs Are Compounds Ubiquitously Present As Fused Two Or More Benzene Rings Produced from Natural Sources Like Oil Leakages And Forest Fires Or from Anthropogenic Sources Like Burning Of Coal Tar, Fossil Fuel, Wood And Used Lubricating Oil. Pahs Are Found In Air, Soil And Water. Pahs Cause Toxic Effects On Human, Animals And Plants. Anthracene As A Member Of Pahs, Has Toxic Effects On Tissue And Skin And May Cause Toxic Effects On Some Eukaryotic Microorganisms’ Growth.
Bioremediation Is One Of The Ways Used To Remove Toxic Compounds, where Microorganisms Degrade Toxic Compounds By Oxidative Pathways Through Monooxygenase Or Dioxygenase Enzymes In order To Obtain Their Energy Source. Bioremediation Is A Cheap And Clean Technique.
In This Study, We Isolated Three Bacterial Isolates from Beni-Suef City, Egypt, Which Have The Capability To Degrade Anthracene. The Three Isolates Were Named Bm1, Pm1 And Mm1. The Three Isolates Identified By 16s Rrna As Brevibacillus Sp. (Bm1), Pseudomonas Sp. (Pm1) And Methylocystis Sp. (Mm1).
In order To Determine The Degradative Capacity Of The Three Isolates, A Culture Of Each Of The Three Isolates In Msm With 50µg Ml-1 Anthracene At 30ºc And Shaking With 160 Rpm Was Followed Up For Six Days And The Residual Anthracene Was Measured By Hplc. Of Note, The Three Isolates Showed A High Potential To Biodegrade Anthracene Under Aerobic Conditions, where 94.58%, 94.53%, And 99.61% Of The Starting Anthracene Concentration Was Degraded Within Six Days By Brevibacillus Sp., Pseudomonas Sp., And Methylocystis Sp., Respectively.
To Enhance The Growth And The Biodegradation Ability Of The Three Isolates, Different Incubation Conditions Were Followed Up For Six Days And Measured By Od And Hplc, Respectively. The Culture Was Formed Of Each Of The Three Isolates With 50µg Ml-1 Anthracene In Msm. The Conditions Were Shaking 30ºc, Shaking 25ºc, No Shaking And Carbon Or Nitrogen Source Supplementation As 0.1% Glucose Or 0.1% Yeast. As A Result, Either The Shaking Or Supplementing The Media With Carbon Or Nitrogen Source Could Obviously Increase The Growth Of The Three Isolates. The Condition Of Shaking At (160rpm) As An Aeration Source, Also, Enhanced The Biodegradation Activity Of The Three Isolates More Than The No Shaking Condition. On Other Hand, Supplementing The Media With Other Carbon Or Nitrogen Source As Glucose Or Yeast Has No Apparent Significant Increase In The Biodegradation Efficacy. For Example, Anthracene Utilization In Brevibacillus Sp. With 0.1% Yeast Or Glucose Was Lower Than That Of Only Anthracene Msm Media At 30oc. In The Case Of Pseudomonas Sp., Anthracene Degradation At 30oc Shaking Incubation Was Near To 0.1% Yeast Supplementation Condition. Such A Result Was Confirmed By Another Previous Study.
In order To Predict The Biodegradation Pathway Of The Three Isolates, The Resulted Intermediates Were Detected By Gc-Ms Technique. from The Detected Intermediates, Were Phthalic Acid, Benzoic Acid Derivative And Other Phenolic Compounds. Such Intermediates Were Involved In Previous Studies And Previous Predicted Pathways.
Some Biodegrading Genes Were Detected In Our Study By Pcr Gene Amplification Method. Tnpa-Like Gene, Tadq-Like Gene, Acin Gs-Like Gene, Tadr-Like Gene, And
Tadq2-Like Gene, Were Detected In Brevibacillus Sp. While Pseudomonas Sp. Revealed The Presence Of Only Acin Gs-Like Gene. On The Other Hand, Tnpa-Like Gene, Tadr-Like Gene, Tadq-Like Gene, Ps Pass 2.3-Like Gene, Gs2-Like Gene, And Acin Gs-Like Gene Were Found In Methylocystis Sp. Where, Tadr Gene Is Responsible For Dioxygenase Gene Expression. Tadq Gene Is An Oxygenase Encoding Gene.
from This Study, The Three Isolates Could Degrade Anthracene To Promising Levels. So, Bioremediation Using These Three Isolates Is A Promising Method To Remove Pollution from The Environment.