08.08.2015   Advanced Biofuels and Bioproducts

Heterokont (Brown Algae, Yellow-Green Algae, Golden Algae, Diatoms, and Others)

Heterokonts are a large and very diverse group of algae identified relatively recently that possess similar morphology, photosynthetic pigments, ultrastructural features, and genetic code [50, 51] . Several Heterokont groups of algae correspond to for­merly distinct phylum, the Chrysophyta and Phaeophyta. The species are wide­spread in brackish water, freshwater, marine and terrestrial habitats. And chlorophyll a and c are the main photosynthetic pigments, and the main carotenoids are fucox — anthin or vaucheriaxanthin [52] (Tables 11 and 12).

Several Heterokont algae are used in mariculture. Isochrysis galbana, Chaetoceros muelleri, as well as diatoms Skeletonema costatum, Nitzschia and Navicula spp. are used to feed molluscs; Nannochloropsis is used to feed rotifers [53]. In the past

Species

Reactor type

(g/m-day)

P™,u„e (g/L-day)

References

Chlorella sorokiniana

Outdoor inclined tubular photobioreactor (6 L)

50

1.5

[550]

C. sorokiniana

Outdoor helical tubular (14 L)

25.2

0.9"

[551]

Chlorella sp. (,strain P12)

Outdoor open thin-layer (400 L)

22.8

3.8

[552]

Chlorella sp. (,strain P12)

Outdoor open thin-layer (2 m3)

38.2

4.3

[553]

Chlorella vulgaris

Open pond

—

0.18

[510]

C. vulgaris

Flat-panel airlift (1 L)

17

0.56"

[554]

Haematococcus pluvialis

Enclosed parallel tubular (75 m3)

13

0.05

[555]

H. pluvialis

Outdoor airlift tubular (25 m3)

10.2

0.08"

[556]

Scenedesmus obliquus

Open pond

—

0.09

[510]

Dunaliella tertiolecta

Open pond

—

0.12

Chlorella, Scenedesmus

Open pond, nutrients (20-80 m2)

8.6

—

[557]

Scenedesmus

Agricultural tile drainage

10

—

[558]

Scenedesmus and Coelastrum (Kuwait)

High rate wastewater pond (50 m2)

15(30"“)

—

[469]

Scenedesmus and Coelastrum (Kuwait)

High rate wastewater pond (50 m2)

24(38"“)

—

[470]

T suecica

Outdoor annular columns (960 L)

38.2

0.42

[559]

T suecica

Outdoor flume, nutrients (48 m2)

26.2b

—

[11, 12]

Same, with foil arrays

33b (44b)"“

—

Neochloris oleoabundans

Flat-panel airlift (1 L)

16.5

0.55

[560]

N. oleoabundans (N starvation)

Flat-panel airlift (1 L)

5.4

0.18

Chlorococum littorale

Outdoor dome shaped (130 L)

10.95

0.095

[561]

C. littorale

Outdoor parabola shaped (70 L)

14.9

0.09

C. littorale

Outdoor pipe shaped (70 L)

20.5

0.146

Ulva lactuca

Tank, aerated, nutrients (0.7 m3)

17

—

[562]

Same, non-aerated

6.8

—

U. lactuca

Pond (800 m2)

7-24(18.3"“)

—

[563]

Ulva (Florida)

Same, nutrients (2.4 m3)

15-25

—

[483, 564]

Ulva (Florida)

Same, AD effluent (2.4 m3)

15-25

—

U. lactuca and Enteromorpha spp.

Natural populations

0.3-1.7

—

[529]

Enteromorpha Ища, E. prolifera, Percursaria percursa

Tanks (400 L), wastewater 0-40%

і 5"“

—

[565]

Table 9 Productivity of Chlorophyta species

“Estimated from data given in the paper

bEstimated from data given in the paper using a VS/TS ratio of 0.9

882 P. Bohutskyi and E. Bouwer

several decades, diatoms were studied for the production of pharmaceuticals, health products, biomolecules, nanomaterials, and bioremediators [54]. Several diatoms and Pinguiophyceae species have large biotechnological potential due to their high content of eicosapentenoic acid [55, 56] .

The brown algae (Phaeophyceae) are among the most cultivated algal species. Several brown algae were found to be good feedstock for AD. The composition of several species is presented in Table 13.

The alginate is a linear (1-4)-linked glycuronan composed of b-1,4-D-mannuronic acid and a-1,4-L-guluronic acid [57]. Mannitol is an alcohol.

Fucoidan structure varies in different algal species. Generally, it is a nonuni­formly branched and sulfated polysaccharide with backbone composed of alternat­ing 1-3- and 1-4-linked a-L-fucopyranosyl units [58, 59] (Table 14).