Ecophysiological characteristics of red, green, and brown strains of the Baltic picocyanobacterium <i>Synechococcus</i> sp. – a laboratory study

Śliwińska-Wilczewska, Sylwia; Cieszyńska, Agata; Maculewicz, Jakub; Latała, Adam

doi:https://doi.org/10.5194/bg-15-6257-2018

Articles | Volume 15, issue 20

https://doi.org/10.5194/bg-15-6257-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-15-6257-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 15, issue 20

Research article

|

26 Oct 2018

Research article |

| 26 Oct 2018

Ecophysiological characteristics of red, green, and brown strains of the Baltic picocyanobacterium Synechococcus sp. – a laboratory study

Sylwia Śliwińska-Wilczewska, Agata Cieszyńska, Jakub Maculewicz, and Adam Latała

Download

Final revised paper (published on 26 Oct 2018)
Supplement to the final revised paper
Preprint (discussion started on 08 Feb 2018)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC1: 'Pcy manuscript', Cristiana Callieri, 26 Feb 2018
- AC3: 'The responses to he comments of Reviewer 1', Agata Cieszyńska, 21 Mar 2018
RC2: 'Ecophysiological characteristics of red, green and brown strains of the Baltic picocyanobacterium Synechococcus sp. – a laboratory study', Anonymous Referee #2, 06 Mar 2018
- AC2: 'The responses to the comments of Reviewer 2', Agata Cieszyńska, 21 Mar 2018

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (12 Apr 2018) by Koji Suzuki

AR by Agata Cieszyńska on behalf of the Authors (27 Apr 2018) Author's response Manuscript

ED: Referee Nomination & Report Request started (02 May 2018) by Koji Suzuki

RR by Anonymous Referee #3 (28 May 2018)

ED: Reconsider after major revisions (08 Jun 2018) by Koji Suzuki

AR by Agata Cieszyńska on behalf of the Authors (11 Jul 2018) Author's response Manuscript

ED: Referee Nomination & Report Request started (13 Jul 2018) by Koji Suzuki

RR by Douglas Campbell (23 Jul 2018)

Suggestions for revision or reasons for rejection

Figure 1: Information rich figure.
The 3 strains show different salinity/temperature/light niches
BA120 peaks at ~190 uE, 25C, with niche volume widest at 3-8 PSU
BA124 peaks at ~250 uE, 25C, limited effect of salniity
BA132 peaks at ~280, 25C, widest niche at 3 PSU

Given the distributions one might have wished that the temperature scale went higher to better delimit upper temperature limits; a suggestion for future studies.

Figure 2: information rich figure.
Chl peaks at low light. different temperature effects across strains.

Figure 3. Interesting.
One wonders why Car cell-1 peaks at low light for most strains.

Fig. 6 nice to include both chl-1 and cell-1 specific O2 rates; clearly different.

Abstract
Line 18: 'realistic', not 'real'

introduction;
Line 51: 'morphotypes'?? perhaps 'pigment types'? 'morpho' implies morphology
Same comment on line 63; is 'pigment' part of 'morphology'; maybe 'phenotype'

Materials & Methods:
"The PCY cultures were adapted to the various synthetic environmental conditions for two days. "
How many rounds of cell division occurred during the 2 days of acclimation?
What was the growth state of the cultures before the inoculation into the treatment condition?
Some combinations might have still been in lag phase after 2 days, depending upon the state of the preculture and the severity of the stress.

"The salinity was 120 controlled by salinometer (inoLab Cond Level 1, Weilheim in Oberbayern, Germany). "
Controlled by? Or verified by? Controlled by implies a chemostat type titrator. I think the authors mean they used a salinometer to measure the salinity, not ongoing adjustment of salinity?

What was the photoperiod, and when in the subjective photoperiod were measures taken?

"In order to achieve the most reliable results, test cultures were grown in three replicas and were incubated for one week at 135 each combination of light, temperature and salinity. "
OK, good.
How does this relate to the earlier statement about 2 days?

Figure 1, and first section of results:
Were all replicates initially inoculated at equal cell densities?

Line 142
The flow cytometry was used to establish the initial number of picocyanobacteria cells and to measure the final cells concentration after the incubation period.

It would be more generally useful to express:
mu =( ln(Cellsfinal) - ln(Cells initial))/elapsed time
This assumes steady exponential growth over the entire time window.

Then, ln2/mu = apparent generation time.
Then elapsed time/generation time = number of generations achieved under each treatment.
Or, the ratio of Cellsfinal/Cellsinitial, as a direct measure of the fold change in biomass.

Any of these metrics would give better comparability across studies.

Instead doing statistics on the achieved final number of cells, without clear reference to the starting number of cells, is methodologically odd and makes comparisons with other studies difficult.

The masses of statistical comparisons make the results almost unreadable.
I wonder if the authors should lift out the masses of statistical comparisons into tabular or supplement form, and use a much shorter text to descibe the main quantitative and qualitative findings, with reference to a table of statistical tests.

Discussion:
"Carotenoids have a dual role in the cell: to maintain a high 599 capacity for photosynthetic light absorption and to provide protection against photooxidation '
I do not know of any evidence that carotenoids can serve in photosynthetic light absorption in cyanobacteria.
If that is true it needs to be backed by a citation.

best regards, Doug Campbell

Hide

ED: Reconsider after major revisions (23 Jul 2018) by Koji Suzuki

AR by Agata Cieszyńska on behalf of the Authors (26 Aug 2018) Author's response Manuscript

ED: Referee Nomination & Report Request started (30 Aug 2018) by Koji Suzuki

RR by Douglas Campbell (30 Aug 2018)

ED: Publish subject to technical corrections (18 Sep 2018) by Koji Suzuki

Dear Dr. Cieszyńska,

It is a great pleasure now to accept your manuscript for publication in Biogeosciences. Prof. Douglas Campbell as the last referee was well satisfied with your modifications except one line (see below). I agreed to the final comment from Prof. Campbell and also gave some editorial comments on your abstract. So please consider to amend these before publishing your manuscript.

- Comment from Prof. Douglas Campbell:

The authors addressed my concerns. They still include one line:
L526–52: Carotenoids have a dual role in the cell: to maintain a high capacity for photosynthetic light absorption and to provide protection against photooxidation (Siefermann-Harms, 1987; Kana and Glibert, 1988; Jodłowska and Latała, 2010)

and I do not think it is true for cyanobacteria. The cited references do not show that carotenoids act as photosynthetic antenna, rather they show that carotenoid content varies with light acclimation. In many cyanobacteria some carotenoid content is not even in the thylakoid membrane, and I do not know any evidence that shows coupling of carotenoids to photosynthetic light capture in cyanos.

- Editorial comments:

L13: The present study examined …
L14: Remove “was conducted”.
L19 and L23: among strains.

Congratulations, and thank you again for choosing Biogoesciences as an outlet of your excellent work.

Sincerely,

Koji Suzuki
Associate Editor

P.S. Please accept my sincere apologies for the late decision on your manuscript, because a big earthquake with the magnitude of 6.7 hit our island ca. 10 days ago, and it disabled our systems including electricity and water supplies for a while. I am sorry for this inconvenience and thank you for your patience.

Hide

AR by Agata Cieszyńska on behalf of the Authors (23 Sep 2018) Author's response Manuscript

Download

Article (9451 KB)
Full-text XML

Short summary

The present study describes responses of picocyanobacteria (PCY) physiology to different environmental conditions. The cultures were grown under 64 combinations of temperature, irradiance in a photosynthetically active spectrum (PAR), and salinity. The results show that each strain of Baltic Synechococcus sp. behaves differently in respective environmental scenarios. The study develops the knowledge on bloom-forming PCY and reasons further research on the smallest size fraction of phytoplankton.