Potentials of Marine Fungal-like Protists in

Production of Fatty Acids

Guangyi Wang

Prof. & Director Center for Marine Ecology

School of Environmental Science & Engineering

Tianjin University, Tianjin, China

2014 Bio Pacific Rim Summit, December 7-9, San Diego, USA

Marine Thraustochytrids heterotrophic, unicellular, marine (fungal-

like) protists;

play active role in decomposing detritus

matters by produce diverse hydrolytic

enzymes;

Producing diverse hydrolytic enzymes

and fatty acids.

Marine Labyrinthulomycetes

Photomicrograph of an acriflavine-

stained thraustochytrid cell

(marked by arrow) from a natural

sample on a black filter

membrane (Demare, 2008)

10 µm

Labyrinthulomycetes

(mainly marine)

Labyrinthulids

Thraustochytrids

20.6x10-12 g carbon/cell

3.02x10-15 g carbon/cell (Bac)

Biomass of thraustochytrids in marine

habitats

Raghukumar, 2002

2.6 µg C/ml

27 µg C/ml

=682aplanochytrids

Thraustochytrids Abundance

No. of cells (per litre) Habitat Reference

56 X103 Coastal Oceanic waters off Japan Naganuma et al. (1998)

50 X103 Coastal Oceanic waters off Japan Kimura et al. (1999)

21.4 X103 Coastal Oceanic waters off Japan Kimura et al. (2001)

130 X103 Arabian Sea Raghukumar et al. (2001)

42.3 X103 Sandy shores of Mediterranean Sea Bongiorni et al. (2004)

230 X103 Greenland and Norwegian Seas Naganuma et al. (2006)

674 X103 Equatorial Indian Ocean Damare and Raghukumar (2008)

630X103 North Pacific subtropical Ocean off Hawaii Li et al. (2013)

320 X103 Coastal Oceanic waters of Pearl River Delta Liu et al. (2014a)

Thraustochytrids (cont’d)

CTD stations in the equatorial Indian Ocean

during the cruise of ORV Sagar Kanya.

October 2004

Abundance in the equatorial

Indian Ocean

CTD stations in the equatorial Indian Ocean

during the cruise of ORV Sagar Kanya.

October 2004

16.1 µg C/L15.8 µg C/L

94.4 % of

Thr+Bac

Damare & Raghukumar, 2008

Thraustochytrids (cont’d)

September 2006

September 2003

October 2004

Relationship between

thraustochytrids and bacteria

varied with sampling time.

Biotic and abiotic factors, which

affect the abundance of

thraustrochytrids, remain unknow.

Thraustochytrids (cont’d)

Vertical distribution of thraustochytrids

in Hawaiian waters (Li et al, 2013)

Thraustochytrids (cont’d)

(Li et al, 2013)

Thraustochytrids (cont’d)

Living styles Low diversity(Li et al, 2013)

Thraustochytrids (cont’d)

1

PKU#Sed1 (JX847370)

PKU#SW7 (JX847377)

Aurantiochytrium limacinum (JN986842.1)

Aurantiochytrium sp. (FJ821477.1)

Aurantiochytrium sp. (FJ821476.1)

Thraustochytriidae sp.(AY705781.1)

PKU#SW8 (JX847378)

PKU#Mn15 (JX847367)

PKU#Mn35 (JX847369)

Schizochytrium limacinum (HM042908.2)

PKU#Mn4 (JX847360)

Schizochytrium limacinum (HM042912.2)

Schizochytrium limacinum (HM042906.2)

Schizochytrium sp. (DQ023620.1)

Schizochytrium sp. (DQ023618.1)

Schizochytrium limacinum (HM042914.2)

Schizochytrium sp. (FJ039523.1)

Schizochytrium limacinum (HM042913.2)

Aurantiochytrium sp. (FJ821478.1)

Aurantiochytrium sp. (HM126528.1)

PKU#Mn11 (JX847366)

Aurantiochytrium sp. (AB362211.1)

Aurantiochytrium sp. (JQ898299.1)

Thraustochytriidae sp. (AY705763.1)

Thraustochytriidae sp. (AY705780.1)

PKU#Mn16 (JX847368)

PKU#SW1 (JX847371)

Thraustochytrium sp. (FJ821487.1)

Thraustochytrium sp. (FJ821482.1)

PKU#SW2 (JX847372)

Thraustochytrium sp. (AY773276.1)

Labyrinthula sp. (FR875360.2)

Aplanochytrium sp. (FJ810216.1)

82

50 54

53

92

83

60

54

75

100

100

100

0.005

Dynamics and phylogenetic phylogenetic analysis of thraustochytrid

isolates from China coastal waters.

Thraustochytrids (cont’d)

11%

52% 57%

Thraustochytrid frequency and biomass

with respect to bacterial biomass during

three cruises (Damare 2008).

We are likely ignoring

more than half of

secondary production in

the oceans!!!!

Thraustochytrids (cont’d)

0 1 2 3 4

0.0

0.2

0.4

0.6

0.8

CM

Cas

e ac

tivit

y (

μm

ol

ml-1

min

-1)

Time (Day)

PKU#Mn4

PKU#Sed1

PKU#SW1

PKU#SW2

0 1 2 3 4

0

5

10

15

20

25

30

lipas

e ac

tivit

y (

U m

l-1)

Time (Day)

Tween 20

Tween 80

Triton X-100

Nonidet P-40

Na deoxycholate

0 1 2 3 4 5

0

2

4

6

8

0

50

100

150

200

250

OD

660

Time (Day)

OD660

PKU#Mn4 PKU#Sed1

PKU#SW1 PKU#SW2

EPS

PKU#Mn4 PKU#Sed1

PKU#SW1 PKU#SW2

EP

S (

μg/m

l)

Thraustochytrids (cont’d)

Fatty acid profile

Nile red staining

Liu et al, 2013

palmitic acid (16:0)

myristic acid (14:0)pentadecyclic acid (15:0)

palmitoleic acid (16:1),

Oleic acid (18:1)

stearic acid (18:0)

DHA (22:6 ω-3).

Thraustochytrids (cont’d)

The biomass accumulation (represented by lines) and total fatty acid content of dry cell weight (represented by bars) of Aurantiochytrium sp. SW7 and Thraustochytriidae sp. Mn16 in the presence of varying temperature (a), initial pH (b), salinity (c), and glucose concentration (d). (Liu et al. 2014)

Thraustochytrids (cont’d)

DHAyield (represented by lines) and DHA content in TFA (represented by

bars) of Aurantiochytrium sp. PKU#SW7 and Thraustochytriidae sp.

PKU#Mn16 in the presence of varying temperature (a), initial pH (b),

salinity (c), and glucose concentration (d) (Liu et al).

Summary on Thraustochytrids

1. Significant role in ocean carbon cycling and seconday

production (frequency and biomass), but with low

diversity;

2. Rich in fatty acids and potential application in DHA

and biodiesel production.

Acknowledgements

Reform and Development Commission of Shenzhen

Municipal Government (China);

Natural National Science Foundation of China;

Hawaii Marine Renewable Energy Test Center-USDOE;

Designated Marine Industrial R&D Program of State

Oceanic Administration (China).

Thank You!