The sponge holobiont in a changing ocean: from microbes to ecosystems

Microbiome

Table 1 Core functions of the sponge microbiome

	Core function	Interpretation	Reference
Metabolic features	Nitrogen metabolism with emphasis on ammonia oxidation	Utilization of environmental and host-derived nutrients	Reviewed in [77]
	Carbon metabolism with emphasis on complex carbohydrates	Utilization of environmental and host-derived nutrients	[32, 33]
	Nitrogen and carbon metabolism utilizing creatinine	Utilization of environmental and host-derived nutrients	[35, 53]
	Vitamin synthesis (especially thiamine and vitamin B12)	Overproduction of vitamins that are then utilized by the sponge host	[31, 53, 72]
	Secondary metabolism	Microbe-microbe interaction, defense of the holobiont
	Carnitine (vitamin BT) utilization	Utilization of host-derived component	[33]
Defense features	CRISPR-Cas systems	Defense against viruses/phages	[31, 33, 61]
	Toxin-antitoxin systems	Defense against foreign DNA	[31, 33, 61]
	Restriction modification systems	Defense against foreign DNA	[31, 33, 61]
	Eukaryotic-like protein domains	phagocytosis evasion	[31, 54, 81,82,83]
	Modifications of the lipopolysaccharide	phagocytosis evasion	[83, 84]
Other	Mobile genetic elements and transposases	Increased levels of horizontal gene transfer	[31, 53, 61, 85]

ISSN: 2049-2618