Table 3.

Compilation of major operational taxonomic units (OTUs) from each family, their associated identity and potential function/role in carbon cycling. No information (ND) was found for most of the OTUs that are associated with uncultured bacterium/archaeon.

Phylum/class	Family	OTU	Associated species	Accession no.	Function/role
Acidobacteria	Koribacteraceae	23,592	Uncultured bacterium	MH532163.1	ND
		38,977	Uncultured bacterium	FJ166836.1	ND
Alphaproteobacteria	Beijerinckiaceae	30,093	Methylovirgula ligni	CP025086.1	(a) Utilize reduced carbon substrates with no carbon–carbon bonds as sole source of carbon and energy (b) Major carbon source is methanol, which is produced from decomposition of fallen woody materials and plant debris (c) Capable of atmospheric nitrogen fixation (Lidstrom91, Vorob’ev et al.92)
	Hyphomicrobiaceae	3769	Rhodoplanes oryzae	NR_134156.2	(a) Can undergo photoorganoheterotrophy or chemoorganoheterotrophy (Srinivas et al.93)
	Rhodospirillaceae	17,532	Uncultured bacterium	MF439272.1	(a) Can undergo photoorganoheterotrophy or chemoorganoheterotrophy (b) Photoassimilate simple organic compounds under anaerobic conditions (Biebl and Pfennig63, Baldani et al.62)
		23,729	Uncultured bacterium	HQ629097.1
		14,249	Uncultured bacterium	JQ384202.2
	Caulobacteraceae				(a) Ability in degrading hemicellulose, cellulose and lignin (Wilhelm et al.64)
Betaproteobacteria	Burkholderiaceae	18,034	Paraburkholderia metalliresistens	MN661271.1	(a) Assimilates 1-aminocyclopropane-1-carboxylate (ACC), which indirectly promotes plant growth (b) Resistant to metals and has phosphate-solubilizing ability (Guo et al.94)
		28,966	Paraburkholderia oxyphila (Burkholderia oxyphila)	NR_112887.1	(a) Able to transforms catechin, a component of tannins into taxifolin through a two-step oxidation process under the acidic conditions of a forest soil in Japan (b) Catabolizes various aromatic compounds such as catechin, vanilic acid, protocatechuic acid, p-hydroxybenzoic acid, 4-hydroxy-3-methoxycinnamic and trans-pcoumaric acid (Otsuka et al.54, Sawana et al.55)
		40,794	Burkholderia arboris	NR_042634.1	(a)Assimilates L-arabinose, D-mannitol, N-acetylglucosamine, maltose, caprate and phenylacetate (b)Produces pyocelin, a bacterial siderophore with bioactivities from generation of reactive oxygen species. These pyocelin damage plant tissues and is linked to pine wilt disease (Vanlaere et al.95, Mannaa et al.96)
	Neisseriaceae	21,128	Aquitalea pelogenes	MN42817.1	(a)Most active cellulose degrader involved in rapid plant litter degradation (b) Produces glycoside hydrolases that are involved in the complete enzymatic hydrolysis of cellulose (c) Have significantly higher β-d-glucosidase and cellobiohydrolase activity (Woo et al.68, Sedláček et al.97)
		37,359	Aquitalea magnusonii	MN709239.1	(a) Possesses genes for metabolisms of various organic acids, protein amino acids, carbohydrates and aromatic compounds (b)Plant growth-promoting characteristic with the genes for auxin biosynthesis and phosphorus supply (Lau et al.98, Ishikawa et al.56)
		29,610	Neisseriaceae bacterium	KM187040.1	ND
Deltaproteobacteria	Syntrophobacteraceae	47,345	Uncultured bacterium	AB364730.1	ND
		18,121	Uncultured bacterium	AB364730.1	ND
		47,874	Uncultured bacterium	LK024886.2	ND
Planctomycetes	Isosphaeraceae	53,553	Uncultured bacterium	MH528390.1	ND
		3315	Uncultured bacterium	KX823823.1	ND
Actinobacteria	Actinomycetales	23,507	Uncultured bacterium	LR589816.1	ND
		55,000	Micrococcus sp.	LC484762.1	(a) Produces cellulase and xylanase for lignocellulose degradation (b) Plant growth promoting ability (Dastager et al.99, Mmango-Kaseke et al.100)
	Acidimicrobiales	47,380	Uncultured bacterium	HG324890.1	ND
Firmicutes	Bacillaceae	7818	Bacillus aerius	NR_118439.1	(a) Produces endoglucanase that are important for the initiation of cellulose hydrolysis (Oke et al.101)
	Paenibacillaceae	46,383	Paenibacillus tyrfis	MN428219.1	(a) Produces active antimicrobial metabolites, plant growth promoting hormones and insecticides (Aw et al.102, Haruna et al.103)
Nitrospirae	Thermodesulfovibrionaceae	46,238	Uncultured bacterium	AB364847.1	ND
		12,777	Uncultured bacterium	JQ801065.1	ND
		12,230	Uncultured bacterium	KC161617.1	ND
Crenarchaeota	MBGA	27,465	Uncultured soil archaeon	HQ614127.1	ND
		6922	Uncultured bacterium	MH532224.1	ND
		25,348	Uncultured bacterium	MH532218.1	ND
	MCG	55,141	Uncultured soil archaeon	MK527582.1	ND
		50,789	Uncultured soil archaeon	KF640358.1	ND
		23,899	Uncultured soil archaeon	AB600448.1	ND
Euryarchaeota	Methanomassillicoccaceae	15,675	Uncultured soil archaeon	AB364937.1	(a) Available in pure culture. Uses H2 as electron donor but is not able to reduce CO2 to CH4 (b) Ability to reduce methanol to CH4 and also contain complete sets of genes for the degradation of methylamines to CH4 and NH3 (Iino et al.104, Borrel et al.90, Nobu et al.105)