Alain K, Callac N, Ciobanu MC, Reynaud Y, Duthoit F, Jebbar M (2011) DNA extractions from sub seafloor sediments: novel cryogenic-mill- based procedure and comparison to existing protocols. Journal of Microbiological Methods 87: 355–362.

Alawi M, Schneider B, Kallmeyer J (2014) A procedure for separate recovery of extra-and intracellular DNA from a single marine sediment sample. Journal of Microbiological Methods 104: 36–42.

Anonymous (2010) Gel Compar II Manual version 6.5. Applied Maths, Belgium. Pp. 429.

APHA (2005) American Public Health Association. Standard methods for the examination for water and wastewater. 20^th ed., AWWA, WPCF, Washington, D.C., USA, Pp. 5.14–5.19.

Bergland WH, Dinamarca C, Toradzadegan M, Nordgård ASR, Bakke I, Bakke R (2015) High rate manure supernatant digestion. Water Research 76: 1–9.

Corinaldesi C, Danovaro R, Dell’Anno A (2005) Simultaneous recovery of extracellular and intracellular DNA suitable for molecular studies from marine sediments. Applied and Environmental Microbiology 71: 46–50.

Dong B, Yi J, Dai L, Dai X (2013) Evaluation of several DNA extraction methods for obtaining total community DNA from anaerobic digestion sludge. Procedia Environmental Science 18:  856–863. 

Green SJ, Leigh MB, Neufeld JD (2010) Denaturing Gradient Gel Electrophoresis (DGGE) for microbial community analysis.  In: Timmis KN (Ed.), Handbook of Hydrocarbon and Lipid Microbiology. Springer-Verlag, Heidelberg,   Pp. 4137–4158.

Hejazi SM, Erfan M, Mortazavi SA (2013) Precipitation Reaction of SDS and Potassium Salts in Flocculation of a Micronized Megestrol Acetate Suspension. Iranian Journal of  Pharmaceutical Research 12 : 239–246.

Huttunen S, Lampinen A (2005) Bioenergy Technology Evaluation and Potential in Costa Rica; University of Jyväskylä Printing House, Jyväskylä, Finland.

IAEA (2004)  qPCR workshop for Rumen microbial ecology. International Atomic Energy Agency, Australia Pp 1 – 38..

Lane DT (1991) 16S / 23S rRNA sequencing. In: Nucleic acid techniques in bacterial systematics.  In: Stackebrandt E, Goodfellow M (Eds.), John Wiley, New York, USA, Pp 115–175.

Lansing S, Botero R, Martin JF (2008) Waste treatment and biogas quality in small-scale agricultural digesters. Bioresource Technology 99: 5881–5890. 

Lazarevic V, Gaïa N, Girard M, FrancËois P, Schrenzel J (2013) Comparison of DNA extraction methods in analysis of salivary bacterial communities. PLoS One 8: e67699.

Lever MA, Torti A, Eickenbusch P, Michaud AB, Šantl-Temkiv T, Jørgensen BB (2015) A modular method for the extraction of DNA and RNA, and the separation of DNA pools from diverse environmental sample types. Frontiers in Microbiology 6: 476.

Li  JKK, Johnson T, Yang YY, Shore V (1989) Selective separation of virus proteins and double-stranded RNAs by SDS-KCl precipitation. Journal of Virological Methods 26: 3–16.

Li H, Li Y, Zou S, Li C (2004) Extracting humic acids from digested sludge by alkaline treatment and ultrafiltration.  Journal of Material Cycles and Waste Management 16: 93-100.

Lipp JS, Morono Y, Inagaki F, Hinrichs KU (2008) Significant contribution of Archaea to extant biomass in marine subsurface sediments. Nature 454: 991–994.

Lippke JA, Strzempko MN, Raia FF, Simon SL, French CK (1987) Isolation of intact high-molecular-weight DNA by using guanidine isothiocyanate. Applied and Environmental Microbiology 53 : 2588–2589.

Liu FH, Wang SB, Zhang JS, Zhang J, Yan X, Zhou HK, Zhao GP, Zhou ZH (2009) The structure of the bacterial and archaeal community in a biogas digester as revealed by denaturing gradient gel electrophoresis and 16S rDNA sequencing analysis. Journal of Applied Microbiology 106: 952–966.

McIllroy S, Porter K (2010) DNA and RNA extraction. In: Seviour R, Nielson PH (Eds.), Microbial Ecology of Activated Sludge. IWA Publishing, London, Pp. 343-349.

Morono Y, Terada T, Hoshino T, Inagaki F (2014) Hot-alkaline DNA extraction method for deep-subsea floor archaealc ommunities. Applied and Environmental Microbiology 80: 1985–1994.

Muyzer G, De Waal EC, Uitterlinden AG (1993) Profiling of complex microbialpopulations by denaturing gradient gel electrophoresis analysis of polymerasechain reaction-amplified genes coding for 16S rRNA. Applied and Environmental Microbiology 59: 695–700.

Nand K (1999) Biomethanation from Agro-Industrial and Food Processing Wastes. In: Joshi VK, Pandey A (Eds.), Biotechnology: Food Fermentation Microbiology, Biochemistry and Technology. Educational Publishers and Distributers: Kerala, India, Pp. 1349–1372.

Nielsen MB, Kjeldsen KU, Lever MA, Ingvorsen K (2014) Survival of prokaryotes in a polluted waste dump during remediation by alkaline hydrolysis. Ecotoxicology 23: 404–418.

Ogram A, Sayler GS, Barkay T (1987) The extraction and purification of microbial DNA from sediments. Journal of Microbiological Methods 7: 57–66.

Qiao J, Guo R, Shi X, Qiu Y (2013) Evaluation of DNA extraction and purification methods for corn straw biogas slurry. Advanced Materials Research 773: 113–117.

 Queipo-Ortuno MI, Tena F, Colmenero JD, Morata P (2008) Comparison of seven commercial DNA extraction kits for the recovery of Brucella DNA from spiked human serum samples using real time PCR. European Journal of Clinical Microbiology & Infectious Diseases 27: 109–114.

Shamia IS,  Halabi MN,  El-Ashgar NM (2017) Humic acid determination in some compost and fertilizer samples. IUG Journal of Natural Studies 25: 42–50.

Singh L, Maurya MS, Ramana KV, Alam SI (1995) Production of
biogas from night soil at psychrophilic temperature. Bioresource Technology 53: 147–149.

Singh L, Maurya MS, Sai Ram M, Alam SI (1993) Biogas production from night soil — Effects of loading and temperature. Bioresource Technology 45: 59–61.

Sohrabi M, Nair RG, Samaranayake LP, Zhang L, Zulfiker AHM, Ahmetagic A, Good D, Wei MQ (2016) The yield and quality of cellular and bacterial DNA extracts from human oral rinse samples are variably affected by the cell lysis methodology. Journal of Microbiological Methods 122: 64–72.

Solli L, Håvelsrud OE, Horn SJ, Rike AG (2014) A metagenomic study of the microbial communities in four parallel biogas reactors. Biotechnology for Biofuels 7: 146.

Vanwonterghem I, Jensen  PD, Ho DP, Batstone DJ, Tyson GW (2014) Linking microbial community structure, interactions and function in anaerobic digesters using new molecular techniques. Current Opinion in Biotechnology 27: 55–64.

Vesty A, Biswas K, Taylor MW, Gear K, Douglas RG (2017) Evaluating the impact of DNA extraction method on the representation of human oral bacterial and fungal communities. PLOS One 12: e0169877.

Weaver J (2013) DNA Extraction: Overcoming Obstacles in Microbial Studies. Biotechqniques. http://www.biotechniques.com/news/DNA-Extraction-Overcoming-Obstacles-in-Microbial-Studies/biotechniques-335698.html  (accessed 19 May 2017).

Whitehouse CA, Hottel HE (2007) Comparison of five commercial DNA extraction kits for the recovery of Franciella tularensis DNA from spiked soil samples. Molecular and Cellular Probes 21: 92–96. 

Yeates C, Gillings MR, Davison AD, Altavilla N, Veal DA (1997) PCR amplification of crude microbial DNA extracted from soil. Letters in Applied Microbiology 25: 303–307.

Yu Z, Garcia Gonzalez R, Schanbacher FL, Morrison M (2008) Evaluations of different hypervariable regions of Archaeal 16S rRNA genes in profiling of methanogens by Archaea specific PCR and denaturing gradient gel electrophoresis. Applied and Environmental Microbiology 74: 889–893.

Ziganshina EE, Bagmanova AR, Khilyas IV,  Ziganshin AM (2014)  Assessment of a biogas-generating microbial community in a pilot-scale anaerobic reactor. Journal of Bioscience and Bioengineering 117: 730–736.

Zinder SH (1993) Physiological ecology of methanogenesis. In: Ferry JG (Ed.), Methanogenesis. Ecology, Physiology, Biochemistry and Genetics. Chapman & Hall, USA, Pp. 128–206.